HomeMy WebLinkAboutbocc.ord.048.1999AN ORDINANCE OF THE BOARD OF
COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO,
ADOPTING THE PITKIN COUNTY NOXIOUS WEED MANAGEMENT PLAN
ORDINANCE #99- Y8'
RECITALS
I. The Colorado Weed Management Act (C.R.S. 35-5.5-101, et. seq.) was signed into
state law in 1990 and amended in 1996. Now known as the Colorado Noxious Weed
Act, it states that noxious weeds pose a threat to the natural resources of Colorado.
The Act also directs that the Board of County Commissioners of each county in the
state shall adopt a Noxious Weed Management Plan for all unincorporated land
within the county. The Act directs the Board of County Commissioners to appoint a
local Weed Advisory Board, whose power and duties are as follows:
A) To develop a noxious weed list;
B) To develop a Weed Management Plan for managing designated noxious
weeds;
C) To recommend to the Board of County Commissioners that identified
landowners be required to submit an integrated weed management plan for
managing designated noxious weeds on their properties.
2. Pitkin County established a Weed Advisory Board pursuant to Resolution #91-152,
consisting of five (5) regular members.
3. In March of 1998, by resolution #98-69, the Board of County Commissioners adopted
the Pitkin County Noxious Weed List and began writing a weed management plan for
Pitkin County.
4. Public Works staff provided drafts of the Pitkin County Noxious Weed Management
Plan, dated February 23, 1999, to the following: City of Aspen, Town of Snowmass
Village, Town of Basalt, Colorado Department of Transportation, County
Agricultural Committee, Bureau of Land Management, Forest Service, Eagle County,
and Garfield County for review and comments. In addition, copies were distributed
to the state weed coordinator as well as many homeowners associations and
landscaping businesses in Pitkin County. Comments were received and the Plan was
amended with minor changes as requested by the above agencies.
5. The "Pitkin County Noxious Weed Management Plan" dated August 11, 1999,
provides guidelines for effectively managing designated noxious weeds which
represent a threat to the continued economic and environmental value of lands in
Pitkin County. The plan implements the mandates of the Colorado Noxious Weed
Act by detailing integrated management options for designated noxious weeds. Such
options include education, preventative measures, good stewardship, and control
techniques. It is this plan's intent to incorporate those options that are the least
environmentally damaging yet practical, timely, and economically feasible.
Furthermore, it is the responsibility of all landowners to use integrated methods to
manage noxious weeds, and the responsibility of local governing bodies to assure that
these plants are in fact managed.
6. Adoption of the Plan is necessary to maintain healthy ecosystems and to restore
disturbed native plant communities and habitats. Because noxious weeds tend to be
highly invasive and harmful to native vegetation, such weeds can quickly dominate
many sites and often cause permanent damage to plant communities in Pitkin County.
7. The Board of County Commissioners has the authority to adopt the Plan under
Colorado statutory and constitutional law including, but not limited to, the provision
of the Colorado Revised Statutes, Title 30, Article 11 and 35, and Title 35, Article
5.5.
NOW THEREFORE BE IT ORDAINED by the Board of County Commissioners of
Pitkin County, Colorado that:
1. Pitkin County Noxious Weed Management Plan, dated August 11, 1999, is hereby
adopted;
2. The following criminal enforcement and penalty provisions are adopted as part of the
Plan;
ENFORCEMENT
5.01 Compliance: Private Lands: Management of Noxious Weeds
A. Inspection.
(1) Pitkin County, through its delegates, agents, and employees, shall have the
right to enter upon any premises, lands, or places, whether public or private,
during reasonable business hours for the purpose of inspecting for the existence of
noxious weed infestations, when at least one of the following circumstances has
occurred: (a) The landowner has requested an inspection; (b) A neighboring
landowner or occupant has reported a suspected noxious weed infestation and
requested an inspection; or (c) An authorized agent of the local government has
made a visual observation from a public right-of-way or area and has reason to
believe that a noxious weed infestation exists.
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(2) (a) No entry upon any premises, lands, or places shall be permitted until the
landowner or occupant has been notified by certified mail that such inspection is
pending. Where possible, inspections shall be scheduled and conducted with the
concurrence of the landowner or occupant. (b) If after receiving notice that an
inspection is pending the landowner or occupant denies access to the inspector of
the local governing body, the inspector may seek an inspection warrant issued by
a municipal, county, or district court having jurisdiction over the land. The court
shall issue an inspection warrant upon presentation by the local governing body,
through its agent or employee, of an affidavit stating: The information which
gives the inspector reasonable cause to believe that any provision of this article is
being or has been violated; that the occupant or landowner has denied access to
the inspector; and a general description of the location of the affected land. No
landowner or occupant shall deny access to such land when presented with an
inspection warrant.
B. Management.
(1) If following inspection pursuant to section 5.01(A) land is found to contain
designated undesirable plants, the landowner shall be given written notice,
personally or by certified mail. The notice shall name the undesirable plants,
identify the location of the plants, advise the landowner to control the undesirable
plants, and specify the best available control methods of integrated management.
The notice shall include an offer to consult with the landowner in the development
of a management plan for the control of undesirable plants on the land. The notice
also shall state that the landowner shall, within a reasonable time not to exceed 10
days, either (I) comply with the terms of the notification, (II) acknowledge the
terms of the notification and submit an acceptable plan and
schedule for the completion of the plan for compliance; or (III) request an
arbitration panel to determine the final management plan.
(2) If the landowner chooses action option I, the Pitkin County Land Management
Department, or its representative, will re -inspect the land to confirm compliance.
(3) If the landowner chooses action option II, the Pitkin County Land
Management Department, or its representative will review the proposed weed
management plan and determine its efficacy. If the plan is acceptable, no further
action will be taken except to monitor compliance, including re -inspection.
(4) If the landowner chooses action option III, an arbitration panel will be selected
by the Board of County Commissioners, in accordance with CRS 35-5.5-
109(4)(b). The arbitration panel shall be comprised of a weed management
specialist or weed scientist, a landowner of similar land in the same county, and a
third panel member chosen by agreement of the first two panel members. The
landowner or occupant shall be entitled to challenge any one member of the panel,
and the local governing body shall name a new panel member from the same
category. The decision of the arbitration panel shall be final. A hearing shall be
set for a time and date as soon as practical after The panel is complete. The Pitkin
County Land Management Department, or its representative, shall give written
notice, personally or by mail, of the hearing to any complaintant. The landowner
is entitled to appear before the panel, individually and/or by representative, as is
any complaintant. The arbitration panel will be required to determine the final
management plan not more than two calendar weeks after the hearing is
completed. In the event of non-compliance with any management plan, in
addition to remedies set forth in paragraph 5.01 C the arbitration panel shall have
the ability to award costs of the arbitration to the prevailing party including
arbitration panel fees and expenses. These fees and expenses may include, but are
not limited to, salary, wages, travel, and meal per deim.
C. Failure to Comply.
1. Public Nuisance.
If the landowner fails to comply with the notice to control the designated
undesirable plants, fails to submit an acceptable management plan, fails to comply
with an accepted management plan, or fails to comply with a management plan as
determined by the arbitration panel, the Board of County Commissioners, at a
public hearing at least 10 days after notice thereof to the property owner, may
declare the infested property a public nuisance for which the remedies for
abatement of a public nuisance shall be available as provided in C.R.S. 35-5.5-
113. Once declared, such nuisances are subject to all laws and remedies relating to
the prevention and abatement of nuisances.
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2. Other remedies.
In addition to, or as an alternative to the nuisance remedy Pitkin County may
compel management if the weeds in the following manner: The Pitkin County
Land Management Department, or its representative, shall give written notice of a
hearing before the Board of County Commissioners to the landowner by personal
delivery or by certified mail which will include the date and time of the hearing,
10 days prior to the hearing date. The notice will include (i) description of the
land, (ii) name of the undesirable plants and their location(s) on the land, (iii) date
the Pitkin County Land Management Department, or its representative, will
perform weed control on the land, (iv) method of control to be applied, (v) a
statement that the land will be assessed the entire cost of the weed control plus
20% surcharge for the cost of inspection and other incidental costs, which total
will be a lien on the land (or the tract of which it is a part) until paid, and (vi) a
statement should the landowner refuse admission to the land for application of the
weed control, the County will seek civil and/or criminal penalties and court -
enforced abatement of a public nuisance. Such an assessment under this section
shall have priority over all other liens except general taxes and prior special
assessments, and may be certified by Pitkin County Land Management to the
County Treasurer and collected and paid over in the same manner as provided for
collection of taxes. Costs of providing for and compelling weed management
shall not be assessed until the level of management called for in the notice or as
developed by the arbitration panel has been successfully achieved.
3. Other Occupants.
Whenever the land is known to the Pitkin County Land Management Department,
or its representative, to be occupied by someone other than the record owner,
written notices also shall be given to the occupant, and the occupant shall be
informed that C.R.S. 35-5.5-109 and this regulation imposes on occupants the
same responsibilities for undesirable plant control as it imposes on landowners.
4. Notice.
Whenever notice is given by mail, it shall be deemed given when deposited in a
regular depositary of the United States Postal Service, postage prepaid. Notice to
landowners shall be mailed to the last known address as shown in the County's
Assessment Roll unless the landowner has provided the Pitkin County Land
Management Department a different address for notice. Notice to occupants shall
be mailed to the land's physical address unless the occupant has provided the
Pitkin County Land Management Department with a different address for notice.
5. Condition Precedent.
No private land management shall be compelled without first applying the same
or greater management measures to county land or rights -of -way that are adjacent
to the private property.
5.02 State Public Lands: Compliance of lands owned by the state of Colorado or its
agencies is governed by C.R.S. 35-5.5-110.
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5.03 County Rights -of -Way: It shall be the duty of Pitkin County to confirm that all
county roads, highways, rights -of -way, and any easements appurtenant thereto,
are in compliance with the Colorado Noxious Weed Act and this management
plan, and any violations by the county of this article shall be the financial
responsibility of the county.
3. In accordance with C.R.S. Sec. 30-35-406, one of the three copies of the Pitkin
County Noxious Weed Management Plan, dated August 11, 1999, which has been
maintained by the County Clerk, shall he maintained at the Public Works Office. The
County Clerk shall at all times maintain a reasonable supply of copies of the Pitkin
County Noxious Weed Management Plan, available for the public.
INTRODUCED, FIRST READ, AND SET FOR PUBLIC HEARING, BY THE BOARD
AT ITS REGULAR MEETING ON THE lath DAY OF OCTOBER , 1999.
PUBLISHED, INCLUDING NOTICE OF PUBLIC HEARING, IN THE ASPEN TIMES
ON THE 16th DAY OF OCTOBER , 1999, AND NOTICE OF PUBLIC
HEARING ONLY ON THE 27th DAY OF OCTOBER , 1999.
APPROVED AND ADOPTED UPON SECOND READING AND AFTER A DULY -
NOTICED PUBLIC HEARING BY A MAJORITY OF THE BOARD AT ITS
REGULAR MEETING ON THE 27th DAY OF OCTOBER , 1999.
PUBLISHED, BY TITLE ONLY, AFTER ADOPTION IN THE ASPEN TIMES ON
THE 6th DAY OF NOVMBER , 1999.
BOARD OF COUNTY COMMISSIONERS
0 PITKIN COUNTY, COS ORADO
--(A L
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Chairperson
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5 a06 By:
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Land Management
Franchon Bliss, Chairperson
Pitkin County Weed Advisory Board
5
AP
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John Ely
County Attorney
MANAGER APPROVAL:
ROVED AS TO FORM:
Sine Konkhan
Co Manager
PITKIN COUNTY NOXIOUS
WEED MANAGEMENT PLAN
Ordinance #99-48
Prepared by Pitkin County Land Manager,
Public Works Administrative Staff,
Pitkin County Weed Advisory Board
Fall 1999
PITKIN COUNTY
NOXIOUS WEED MANAGEMENT PLAN
TABLE OF CONTENTS
SECTION I: Introduction
1.01 Mission Statement 4
1.02 Purpose of the Plan 4
1.03 Enactment Authority 4
1.04 Pitkin County Noxious Weed List 5
SECTION II: Weed Identification
2.01 Written Description of 21 Designated
Noxious Weeds 7
2.02 How to Distinguish Varieties of Thistle,
Knapweed or Toadflax 15
2.03 The Threat of Escaped Ornamentals 16
2.04 Integrated Weed Management —Treatment Methods 16
SECTION III: Geographical Overview of areas of infestation in Pitkin County
3.01 Overview 29
3.02 County Land 29
3.03 Open Space & Trails and Other County Property 31
3.04 Airport 32
3.05 Solid Waste Center 33
3.06 The Roaring Fork Railroad Holding Authority (RFRHA) 33
3.07 State Lands 33
3.08 Federal Lands 35
3.09 Municipalities 36
SECTION IV: Plan of Work
4.01 Objectives and Goals 38
4.02 Prevention and Detection 38
4.03 Education and Awareness 39
4.04 Land Stewardship 40
4.05 Revegetation and Rehabilitation 40
4.06 Native Plants 43
4.07 Mapping and Inventory 44
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SECTION V: Enforcement
5.01 Compliance on Private Lands 45
5.02 State Public Lands 48
5.03 County Rights -of -Way 48
SECTION VI: Plan Evaluation
6.01 Plan Evaluation 49
SECTION VII: Resource Directory
7.01 Government & Other Agencies 50
7.02 Help from the Web 51
7.03 Books 51
SECTION VIII: Definitions
8.01 Definitions 52
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SECTION I
INTRODUCTION
1.01 Mission Statement:
The health of our environment is clearly a high priority for residents of the Roaring Fork
Valley. Yet, the health and productivity of our natural plant communities is being
threatened by the introduction of numerous invasive alien plants. Without a major
integrated weed management plan these aggressive plants will continue to infest and
degrade the lands that we value so highly.
The rapid expansion of noxious weeds is one of the greatest obstacles to maintaining
healthy ecosystems and restoring disturbed native plant communities and habitats.
Because noxious weeds tend to be highly invasive and harmful to native vegetation, such
weeds can quickly dominate many sites and often cause permanent damage to plant
communities. At the present time the spread of noxious weeds on BLM lands is estimated
at over 2,300 acres per day, and on all western public lands at approximately 4,600 acres
per day. This is occurring in both disturbed and relatively undisturbed areas.
It is the intention of the Colorado Noxious Weed Act and the goal of the Pitkin County
Weed Advisory Board that by implementing an integrated Weed Management Plan the
destruction of our valued environment will be curbed. The challenge of controlling weeds
may seem overwhelming, but through developing partnerships at all levels —local,
regional, and national —we hope that the likelihood of reaching our collective weed
management goals will be high. The challenge of all involved is to develop management
support and direction for preventing the spread of weeds before the situation becomes
even more serious and economically unfeasible.
1.02 Purpose of the Plan:
The purpose of this Pitkin County Noxious Weed Management Plan is to provide
guidelines for effectively managing designated noxious weeds which represent a threat to
the continued economic and environmental value of lands in Pitkin County. This plan
implements the mandates of the Colorado Noxious Weed Act by detailing integrated
management options for designated noxious weeds. Such options include education,
preventative measures, good stewardship, and control techniques. It is this plan's intent to
incorporate those options that are the least environmentally damaging yet practical,
timely, and economically feasible. Furthermore, it is the responsibility of all landowners
to use integrated methods to manage noxious weeds, and the responsibility of local
governing bodies to assure that these plants are in fact managed.
1.03 Enactment Authority:
The Colorado Weed Management Act (C.R.S. 35-5.5-101, et. seq.) was signed into state
law in 1990 and amended in 1996. Now known as the Colorado Noxious Weed Act, it
4
states that noxious weeds pose a threat to the natural resources of Colorado. The Act also
directs that the Board of County Commissioners of each county in the state shall adopt a
Noxious Weed Management Plan for all unincorporated land within the county. The Act
directs the Board of County Commissioners to appoint a local Weed Advisory Board,
whose power and duties are as follows:
1. To develop a noxious weed list;
2. To develop a Weed Management Plan for managing designated noxious weeds;
3. To recommend to the Board of County Commissioners that identified landowners be
required to submit an integrated weed management plan for managing designated
noxious weeds on their properties.
1.04 Pitkin County Noxious Weed List:
The State of Colorado has three noxious weed lists as designated by rule of the Colorado
Department of Agriculture.
The State has designated 56 plants as State Noxious Weeds. This list is available through
the Pitkin County Land Management Department or the State of Colorado. These weeds
comprise the "A" List. Ten of the fifty-six plants have been prioritized by the State as
being the most widespread and causing the greatest economic impact. These plants are the
"B" list. The third list, "C" contains five plants that are not widespread in Colorado,
however local advisory boards are encouraged to contain and eradicate these species
before they significantly impact the economic and environmental values of the State.
The comprehensive "A" list was determined by an extensive survey of weed managers
throughout Colorado. It is the intent of this list, created by administrative rule, to give each
local governing board the ability to specify from the list, which plants may cause impacts
on a local basis. It is the option of the local governing board to create a designated noxious
weed list, that may contain all or portions of the State's list depending upon the local
situation and priorities. In general terms, most local governing boards adopt a list that
contains the most threatening plants to their area. It would not be practical to expect that
most jurisdictions would be able to dedicate the resources to manage all of the plants on
the comprehensive list.
In addition to the list of weeds designated by the State of Colorado, the Pitkin County
Weed Advisory Board has specified certain plants as noxious weeds in our area. The
plants on this list have been identified as noxious because they are alien plants that present
a threat to the well-being of land within Pitkin County. These noxious weeds are
considered to be aggressive, fast spreading, and capable of displacing native plant species
that provide habitat for wildlife and food for people and livestock.
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The Pitkin County Designated Noxious Weed List includes the following:
1. Leafy Spurge (Euphorbia esula) 12. Poison Hemlock (Conium maculatum)
2. Diffuse Knapweed (Centaurea diffiisa) 13. Dame's Rocket (Hesperis matronalis)
3. Spotted Knapweed (Centaurea maculosa) 14. Scentless Chamomile (Matricaria perforata)
4. Russian Knapweed (Acroptilon repens) 15. Oxeye Daisy (Chrysanthemum leucanthemum)
5. Canada Thistle (Cirsium arvense) 16. Common Tansy (Tanacetum vulgare)
6. Houndstongue (Cynoglossum officinale) 17. Mediterranean Sage (salvia aethiopis)
7. Hoary Cress (Cardaria draba) 18. Yellow Toadflax (Linaria vulgaris)
8. Musk Thistle (Carduus nutans) 19. Dalmatian Toadflax (Linaria genistifolia)
9. Scotch Thistle (Onopordum acanthium) 20. Purple Loosestrife (Lythrum salicaria)
10. Common Burdock (Arctium minus) 21. Field Bindweed (Convolvulus arvensis)
12. Plumeless Thistle (Carduus acanthoides)
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SECTION II
WEED IDENTIFICATION
PITKIN COUNTY'S
21 NOXIOUS WEEDS
Noxious weeds threaten the very reason we live, work, and recreate in the Roaring Fork
Valley. The Pitkin County Weed Advisory Board encourages you to become more
knowledgeable about noxious weeds. Our natural resource heritage depends on your
involvement.
2.01 Written Description of 21 Designated Noxious Weeds:
Canada Thistle (Cirsium arvense)
``' Canada thistle is a member of the Aster family. Canada
thistle was introduced from Europe. It is a creeping
perennial which reproduces by seeds and fleshy,
horizontal roots. The erect stem is hollow, smooth and
slightly hairy, 1 to 5 feet tall, simple, and branched at the
top. The color is primarily lavender, pink, or purple.
Canada thistle emerges in June in most parts of Pitkin
County. It is one of the most widespread and
economically damaging noxious weeds in Colorado.
Infestations are found in cultivated fields, riparian areas,
pastures, rangeland, forests, lawns and gardens,
roadsides, and in waste areas. Because of its seeding
habits, vigorous growth, and extensive underground root
system, control or eradication is difficult.
Common Burdock (Arctium minus)
Common burdock is a member of the Aster family. It is an introduced
biennial which reproduces by seeds. In the first year of growth the
plant forms a rosette; the second year the plant grows erect. Burdock
grows to 6 feet tall, has enormous leaves and a prickly bur. The
flowers are purple and white in numerous heads. Burdock grows
along roadsides, ditch banks, and neglected areas. This plant is a very
serious threat to sheep as the burs can significantly damage the
quality of their wool.
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Common Tansy (Tanacetum vulgare)
Common tansy is a member of the Aster family. Originally
imported from Europe as an ornamental, it is a perennial plant that
grows from 11/2 feet to 6 feet tall with yellow button -like flowers
and fern -like leaves. Reproducing by both seed and rootstock,
tansy is difficult to control. Tansy is particularly aggressive when
growing along irrigation ditches where it can restrict water flow.
Dalmatian Toadflax (Linaria genistifolia)
Dalmatian toadflax is a member of the Figwort family. It was
introduced as an ornamental from Europe, and can be found along
Snowmass Creek Road. It is a creeping perennial with stems from
2 to 4 feet tall. The flowers are snapdragon -shaped, bright yellow,
with orange centers; the leaves are waxy and heart -shaped.
Dalmatian toadflax is especially well adapted to arid sites and can
spread rapidly once established. Because of its deep, extensive root
system and heavy seed production, this plant is difficult to manage.
Dame's Rocket (Hesperis matronalis)
Dame's rocket is a member of the Mustard family and is also
known as dame's violet. This native of Europe may be either
a biennial or perennial, grows from 11/2 to 4 feet tall, and has
flowers ranging in color from white to pink to purple. This
persistent plant is often sold in local nurseries and is found in
wildflower seed mixes. As a result, it has escaped cultivation
and become a problem throughout the Roaring Fork Valley,
tending to invade riparian and wetland habitat.
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Diffuse Knapweed (Centaurea diffusa)
Diffuse knapweed is a member of the Aster family. Diffuse
knapweed was introduced from Europe and is a biennial or
short-lived perennial forb, which reproduces only by seed. The
plant usually produces a single main multi -branched stem that
is 11/2 to 2 feet tall. The flower is white or pink with bracts.
Field Bindweed (Convolvulus arvensis)
Field bindweed is a member of the Morning-glory family.
This creeping perennial was introduced from Europe. It
reproduces by seed and horizontal roots. The stems are 1 to
4 feet long and spread thickly over the ground or wind
around erect plants or other objects. The flowers are bell- or
trumpet -shaped, white or pink. Field bindweed is one of, he
most competitive perennial weeds and is a problem
throughout Colorado. Its roots can extend 10 feet deep and
a two- or three-year food supply is stored in the extensive
underground root system. This makes it hard to kill by cultivation because roots will live as long
as their food reserve lasts. Seeds can also stay viable in the soil for up to 40 years. It is widespread
in cultivated areas, pastures, lawns, gardens, roadsides, and waste areas throughout Pitkin County.
Hoary Cress (Cardaria draba)
Hoary cress, also known as whitetop, is a member of the Mustard
family, and was probably introduced from Europe in alfalfa seed. It
is a creeping perennial which reproduces by seed and creeping
roots. The extensive root system spreads horizontally and vertically
with frequent shoots arising from the rootstock. It grows erect from
10 to 18 inches high and has a gray -white colored leaf. The flowers
are white and numerous in compact flattop clusters which give the
plant its name. Hoary cress is one of the earliest perennial weeds to
emerge in the spring, producing flowers in May or June. It grows
in waste places, cultivated fields, and pastures, and is capable of
vigorous growth.
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Houndstongue (Cynoglossum officinale)
Houndstongue is a member of the Borage family. It is a
biennial that was introduced from Europe. It reproduces
by seed and appears as a leafy rosette in its first year. The
plant grows 1 1/2 to 3 feet high with reddish -purple
flowers. Houndstongue is commonly known as the
"Velcro weed" because of its small nutlets that are rapidly
spread by people, domestic animals, wildlife and
vehicles. Houndstongue grows on ranges, pastures, trails
and roadsides and is toxic to horses and cattle, as it
contains alkaloids that may cause liver cells to stop
reproducing.
Leafy Spurge (Euphorbia esula)
Leafy spurge, a member of the Spurge family, was introduced
from Europe. It is a creeping perennial that reproduces by seed
and extensive creeping roots. The roots can extend as deep as
30 feet on a plant that grows 1 to 3 feet tall, with pale green
shoots and small yellow -green flowers. The plant, including the
root, has milky latex that is damaging to eyes and sensitive skin.
Leafy spurge is an extremely difficult plant to control because
of its extensive sprouting root. It is adapted to a wide variety of
habitats in the state and is very competitive with other plant
species. If it becomes established in rangeland, pasture, and
riparian sites, it may exclude all other vegetation due to its
competitive nature. Widespread from Starwood to Lower Rio
Grande Trail and Jaffee Park to Pitkin Iron Property to Hannon
.Creek in the Woody Creek Valley.
10
Mediterranean Sage (Salvia aethiopis)
Sometimes sold as Ethiopian sage in local nurseries,
Mediterranean sage is an aggressive omamental plant that
has invaded over 1,000 acres of rangeland in northern
Boulder County. A member of the Mint family, this biennial
was introduced from the Mediterranean and North Africa,
and is recognized as a problem in many western states. In the
first year, the seedling develops a rosette of large wooly
leaves that are strongly aromatic. Mediterranean sage
produces a profusion of showy, white flowers during the
second growing season. This weed usually becomes
established in sparsely vegetated land, but will readily invade
rangeland in good condition. Currently not found in Pitkin
County.
Musk Thistle (Carduus nutans)
Musk thistle is a member of the Aster family. Introduced
from Eurasia, it is a winter annual or biennial which
reproduces by seed. The first year's growth is a large,
compact rosette from a large, fleshy, corky taproot. The
second year stem is erect, spiny, 2 to 6 feet tall and branched
at the top. The waxy leaves are dark green with a light green
midrib and mostly white margins; flowers are purple or
occasionally white. Musk thistle is also known as "nodding
thistle" and is commonly found in pastures, roadsides, and
waste places. It prefers moist bottomland soil, but also can
be found on drier uplands. It is found primarily in Old
Snowmass and along the Crystal River.
Oxeye Daisy (Chrysanthemum leucanthemum)
Oxeye daisy, a member of the Aster family, is a native of
Eurasia. It is an erect perennial plant with white ray and
yellow disk flowers which bloom from June through
August. Oxeye daisy is commonly sold in wildflower seed
mixes or transplanted as an ornamental despite its tendency
to crowd out more desirable vegetation.
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Plumeless Thistle (Carduus acanthoides)
Plumeless thistle is a member of the Aster family. Introduced
from Eurasia, it is a winter annual or biennial. This plant can be
distinguished from musk thistle by its smaller flowers from 1/2 to
1 inch in diameter. The leaves of plumeless thistle lack the
prominent white margin present on musk thistle leaves. The
plant may grow to a height of 5 feet or more. Flowers are
reddish -purple and are either solitary or clustered. Taproots are
large and fleshy. Plumeless thistle is an extremely prolific seed
producer. It is found in pastures, river valleys, and along
roadsides. It is a major problem in and around the Aspen area.
Poison Hemlock (Conium maculatum)
Poison hemlock is a member of the Parsnip family,
introduced from Europe. It is a biennial that reproduces solely
from seed. During the first year of growth a large rosette of
leaves is produced; during the second year the plants bolt to
produce 4 to 12 foot stems with white flowers that grow in
small, erect clusters. The stem is mottled with purple spots.
All parts of the plant are poisonous to humans as well as to
wild and domestic animals.
Purple Loosestrife (Lythrum salicaria)
Purple loosestrife is a member of the Loosestrife family. It is
•a perennial introduced from Europe. The erect, square stem
can reach 11h to 8 feet tall with magenta -colored flowers.
Purple loosestrife is a highly aggressive invader species that
can be found in most wetland sites throughout the state. If
left unchecked, a wetland will eventually become a
monoculture of loosestrife, posing a severe threat to
waterfowl habitat and impeding water flow in irrigation
ditches. It can be found as an ornamental plant throughout
the City of Aspen.
12
Russian Knapweed (Acroptilon repens)
Russian knapweed is a member of the Aster family
introduced from Europe. It is a creeping perennial that
reproduces by seed and creeping, horizontal roots. The
ridged stems are stiff and 1 to 3 feet high, with thistle -like
flowers that are lavender to white. It is most common in
Old Snowmass and the Crystal River Valley.
Scentless Chamomile (Matricaria perforata)
Scentless chamomile is a member of the Aster family that was
imported from Europe as an ornamental and now grows
worldwide. It is an annual that grows '/2 to 2 feet tall in a bushy
shape with showy white flowers. It is nearly identical in
appearance to the strong scented species, but can be easily
distinguished by its lack of odor. Scentless chamomile has no
forage value and can cause blistering of muzzles, irritation of
mucous membranes, and skin rashes in livestock. The plant has
become widely established in the City of Aspen.
Scotch Thistle (Onopordum acanthium)
Scotch thistle is a member of the Aster family. It is a biennial
that was introduced from Europe or eastern Asia and can reach
a height of 8 feet. The rosette forms the first year and can have
leaves up to 2 feet long and 1 foot wide. The second year the
plant produces flowers that are reddish -purple to violet. It is
found primarily along roadsides and railroads, but can become
an impassable obstacle to livestock on rangeland and pastures. It
is increasing in densities throughout Pitkin County.
13
Spotted Knapweed (Centaurea maculosa)
Spotted knapweed is a member of the Aster family. Native to
Central Europe, it is a simple perennial that reproduces from
seed and forms a new shoot each year from a taproot. The plant
can have one or more shoots up to 4 feet tall. Flower color is
usually lavender to purple. Spotted knapweed occupies dry
meadows, pastures, stony hills, roadsides, and the sandy or
gravel flood plains of streams and rivers, where soils are light
textured, well -drained, and receive summer precipitation.
Spotted knapweed tolerates dry conditions, similar to diffuse
knapweed, but will survive in higher moisture areas as well.
There is a small infestation up Independence Pass above
Tagerts Lake.
Yellow Toadflax (Linaria vulgaris)
Yellow toadflax is a member of the Figwort family and is sometimes called common toadflax or
butter and eggs. It was introduced from Europe as an ornamental and has now become a serious
problem to rangeland and mountain meadows. It is a
perennial reproducing from seed, as well as from
underground rootstalk. The flowers are bright yellow with
deep orange centers that resemble the snapdragon. Yellow
toadflax does well in all types of soils. Its displacement of
desirable grasses not only reduces ecological diversity, but
also reduces rangeland value and can lead to erosion
problems. Because of its early vigorous growth, extensive
underground root system, and effective seed dispersal
methods, yellow toadflax is difficult to control.
14
2.02 How to Distinguish Varieties of Thistle, Knapweed or Toadflax:
THISTLES
Four types of thistle are on the Pitkin County Noxious Weed List. Canada thistle is a
perennial; it has an extensive root system. Plumeless, Scotch, and musk thistles are
biennials; they are relatively shallow rooted and reproduce by seed only. Canada and
plumeless thistle are often mistaken for each other, however it is very simple to tell them
apart. Canada has a smooth stem; plumeless has spiny stem leaves. The bracts under the
flower of Canada are spineless; the bracts under the flower of plumeless appear as sharp
spines.
The flowers of musk thistle are about three times larger than those of Canada or
plumeless. Musk thistle seedlings have a very prominent white midrib.
Scotch thistle leaves are larger than those of the other thistles. They grow up to 2 feet long
and 1 foot wide. The leaves are covered with dense hairs which give them a gray
appearance.
All of the biennial thistles may grow to heights of greater than six feet. Canada thistle may
grow from 1 to 4 feet tall.
Colorado has several species of thistle which are native and do not cause problems of the
noxious species. Native thistles have mostly white, sometimes very pale lavender flowers
and are more succulent than the noxious species. The flowers may have a hairy or fuzzy
appearance and stems of some species are reddish.
KNAPWEEDS
Russian knapweed is a perennial with an extensive underground root system. Spotted
knapweed is a biennial, or occasionally a short-lived perennial with a short taproot.
Generally, the flowers of spotted and Russian knapweed are pinkish -purple, diffuse
flowers are white, however there are exceptions. The best way to distinguish between the
knapweeds is by the bracts. Bracts are the reduced or modified leaf surrounding the base
of the flower. The bracts of Russian knapweed are white and papery -thin. Diffuse
knapweed has sharp -toothed bracts. Spotted knapweed bracts are more like a fringe (not
as spiny) with a black spot on each bract.
TOADFLAX
The best way to distinguish between the different toadflax is by looking at the shape of
the leaves. Yellow toadflax has narrow leaves that are pointed at both ends; the leaves of
Dalmatian are heart -shaped, clasp the stem, and are waxy with a blue green color. Yellow
toadflax tends to be a smaller plant than Dalmatian toadflax.
15
2.03 The Threat of Escaped Ornamentals
Most plants used for landscaping purposes lack the ability to proliferate outside of the
cultivated environment of the home garden. Yet certain exotic plants and seeds were
imported to the United States for their aggressive growth habits, xeriscape potential, or re-
seeding capabilities. Such plants are known as escaped ornamentals or invasive
ornamentals, and include dame's rocket, common tansy, Mediterranean sage, oxeye daisy,
purple loosestrife, scentless chamomile and toadflax. The very traits which make these
plants desirable for a garden or landscape may also enable them to thrive outside
cultivated areas and become fierce competitors with our native vegetation. Because they
exist here without the presence of any natural predators, these plants have the ability to
spread extensively and pose a severe threat to the delicate balance of our native
ecosystems.
Since various invasive ornamental plants are attractive and establish themselves quickly,
they are popular with landscapers and gardeners and may be purchased through certain
nurseries in the Roaring Fork Valley. It is imperative that we educate landscape architects,
gardeners, and nursery growers about the need to eliminate such plants from their
landscape plans. Otherwise these plants will inevitably escape from the cultivated garden
and jeopardize the natural wildflower and plant communities that we cherish. Native
wildflowers such as Colorado Blue Columbine, our state flower, cannot compete with
invasive ornamental plants for nutrients, sunlight, and water. As a result, our biologically
diverse mountain meadows, grasslands, and wetlands are in danger of being overrun by
non-native invasive ornamental plants.
2.04 Integrated Weed Management —Treatment Methods:
Management techniques include cultural, mechanical, biological and chemical strategies.
The optimum method or methods for weed management will vary depending on a number
of site specific variables. Factors to be considered should include soil type and stability,
grade, associated vegetation, existing and proposed land use, proximity to water,
availability of irrigation water, weed type and stage of growth, and severity of infestation.
The management method selected should be the least environmentally damaging, yet
practical and reasonable in achieving the desired results.
The following recommendations are intended to be a reference for weed management in
Pitkin County. The information is not intended to be a complete guide to weed
management or to herbicide use. Before using any chemical, you should thoroughly read
the label. Any use of an herbicide inconsistent with the label is not legal or recommended.
Changes in herbicide registrations occur constantly. The herbicide label is the legal
document on herbicide use. Read and follow all directions carefully. The use of a
pesticide in a manner not consistent with the label can lead to injury of crops, humans,
animals, and the environment.
16
CANADA THISTLE
Description: Perennial. Reproduces from vegetative buds in root system and from seed.
Comments: Canada thistle is best managed through an integrated management system
that emphasizes competitive, desirable plants.
Biological controls: Three insects currently available. It is best to release a complex of
insects (different insects that will stress different parts of the plant.)
Ceutorhyncus litura—a weevil that stresses the crown of the plant.
Urophora carduii—a stem and shoot gall fly.
Cassidia rubiginosa—leaf beetle.
Chemical controls: There are many effective herbicides that are labeled for Canada
thistle control. For additional information contact your local city,
county or town natural resource office. (See section VII for phone
numbers.)
Cultural controls: Maintain soil fertility and moisture at optimum levels to favor grass
growth.
Mechanical controls: Research indicates that mowing of Canada thistle may be effective
when done repeatedly at two week intervals over a period of several
years. Pulling and digging up Canada thistle has been shown to be
ineffective as the plant has such an extensive root system.
COMMON BURDOCK
Description: Biennial. Prolific seed producer.
Biological controls: None currently available.
Chemical controls: There are many effective herbicides labeled for burdock control.
Chemicals should be utilized prior to bud formation. For additional
information contact your local city, county or town natural resource
office. (See section VII for phone numbers.)
Cultural controls: Minimize soil disturbances, encourage desirable plant growth.
Mechanical controls: Top growth removal through mowing or cutting is effective.
Pulling or digging out the plant at flowering or early seed formation
is effective.
COMMON TANSY
Description: Perennial, escaped ornamental.
Biological controls: None currently available.
17
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Repeated mowing or cutting will inhibit seed production. Pulling or
digging is ineffective.
DALMATIAN TOADFLAX
Description: Aggressive perennial, escaped ornamental.
Comments: Very rare to date in Pitkin County, fairly common in Glenwood Springs.
Biological controls: The defoliating moth, Calophasia lunula, has been released on
Dalmatian and yellow toadflax. It may defoliate up to 20% of the
leaves of the plant.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Early identification is key; since it is rare in Pitkin County, pulling
or digging of individual plants would be effective.
Mechanical controls: Repeated mowing 2-3 times per year will slow spread and reduce
seed production.
Education: The key to Dalmatian toadflax management is to create an awareness
among homeowners, nurseries, landscapers, and landscape architects that
Dalmatian toadflax is a noxious weed and therefore should not be specified
in plantings, sold in nurseries or planted in home gardens or large-scale
landscape projects.
DAME'S ROCKET
Description: Biennial or short lived perennial.
Comments: Best form of control is to riot plant this species. There is little information
currently available on dame's rocket control.
Biological controls:
Chemical controls:
Cultural controls:
Mechanical control:
None currently available.
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Plant native wildflowers or less aggressive plants.
Pulling or digging out the plant at flowering or early seed formation
is effective.
18
Education: The key to dame's rocket management is to create an awareness among
homeowners, nurseries, landscapers, and landscape architects that dame's
rocket is a noxious weed and therefore should not be specified in plantings,
sold in nurseries or planted in home gardens or large-scale landscape
projects.
DIFFUSE KNAPWEED
Description: Biennial, reproduces by seed.
Comments: Very few recorded infestations of diffuse knapweed at this time in Pitkin
County; the early detection and early treatment philosophy could eradicate
this weed in the county.
Biological controls: Two seed head flies Urophora affinis and U. quadrifasciata are
available. They reduce seed production. A root -boring moth
Agapeta zoegana causes considerable damage to roots.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Reseeding of disturbed sites with fast growing grasses helps
prevent diffuse knapweed establishment.
Mechanical controls: None available.
FIELD BINDWEED
Description: A perennial with an extensive underground root system.
Comments: Control by means other than herbicides is difficult. It is best to eliminate
young bindweed plants before they have a chance to develop their
extensive root system. The biggest threat posed by field bindweed in Pitkin
County is to hay producers who are trying to have their hay certified as
weed -free.
Biological controls: None currently available.
Chemical controls:
Cultural controls:
Mechanical controls:
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Re -seed disturbed areas adjacent to field bindweed infestations
with native perennial sod -forming grasses such as Western
wheatgrass.
None available.
19
HOARY CRESS
Description: A very competitive, deep-rooted perennial that reproduces by root
segments and by seed.
Comments: Limited populations in Pitkin County.
Biological controls: None currently available.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls:
Mowing or cultivation effectiveness will be increased if other
plants like perennial native grasses or alfalfa are seeded in the
hoary cress stand as competitors. Maintain range and pasture in
good condition. Promote healthy grass growth through proper
irrigation and fertilization. Do not overgraze.
Mechanical controls: Removal of top growth is somewhat effective. Repeated treatments
may reduce seed production and spread.
HOUNDSTONGUE
Description: Biennial. Prolific seed producer. Seed nutlets break apart at maturity and
cling to clothing or animals.
Comments: Widespread throughout Pitkin County, particularly in areas of past or
current livestock grazing.
Biological controls: None currently available.
Chemical controls: Surfactants highly recommended due to hairiness of leaf. For
additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Re -seed disturbed sites with fast growing native grasses. Maintain
range and pasture in good condition. Promote healthy grass growth
through proper irrigation and fertilization. Do not overgraze.
Mechanical controls: Houndstongue is a prolific seed producer, and the seeds are readily
spread by their ability to stick to wildlife and domestic animals.
Physical removal of the plant at flowering or in early seed
formation, by pulling or digging, will break the cycle of the plant.
LEAFY SPURGE
Description: A perennial up to three feet tall that reproduces by vigorous root stalks
and seed.
20
Comments: Leafy spurge is found primarily in Woody Creek, Starwood, McLain Flats,
Jaffee Park, and Upper River Road. An extremely difficult to control
perennial weed that will require re -treatments to achieve adequate control.
Development of a management plan is helpful to manage large areas of
leafy spurge.
Biological controls: Sheep or goats will graze leafy spurge. If livestock graze leafy
spurge after seed formation, hold animals in a corral for at least
seven days before moving them to an uninfested area to avoid seed
spread.
Several flea beetles Apthona spp. are available from the Colorado
Department of Agriculture Insectary in Palisade. These insects are
available upon request at no charge to the public. The larvae bore
into leafy spurge roots and the adults feed on the leaves. Also
available from the Insectary are Oberea erythrocephala a stem and
root crown mining long -horned beetle, and Spurgia esulae a shoot
tip gall midge. These insects are also available for sale, from
commercial distributors.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Any activity that encourages vigorous grass growth is very
important. Overgrazing stresses grasses and makes them less
competitive to leafy spurge.
Mechanical controls: Mowing leafy spurge at 14 to 21 day intervals may cause higher
susceptibility to fall applied herbicides.
MEDITERRANEAN SAGE
Description: An aromatic biennial or short-lived perennial.
Comments: Presently not found in Pitkin County. May be sold in local nurseries.
Biological controls: A biological control insect, the Mediterranean sage weevil
Phrydiuchus tau has been established on major infestations in
Oregon (1969), California (1974) and Idaho (1979). Its larvae mine
the root, crown, and basal leaf petioles weakening affected plants.
Although heavily infested seedlings and young rosettes die as a
result, the weevil has not stopped the spread of Mediterranean sage.
Chemical controls: Surfactants must be added to help the chemical penetrate the wooly
leaves. For additional information contact your local city, county or
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town natural resource office. (See section VII for phone numbers.)
MUSK THISTLE
Description: Musk thistle is a biennial and the key to its successful management is to
prevent seed formation.
Comments: Populations of musk thistle have been significantly reduced in Snowmass
Canyon and along River Road. Most of the musk found in Pitkin County is
along State Highway 133 and other sites along the Crystal River drainage.
Biological controls: The musk thistle seed head weevil Rhinocyllus conicus is
widespread in Colorado. Larvae of this insect destroy developing
seeds but are not 100 percent effective by themselves. The weevil
normally impacts seed production by about 50 percent. Herbicides
can be combined with weevils if the insects are allowed to complete
their life cycles. Another weevil Trichosirocalus horridus attacks
the crown area of musk thistle rosettes and weakens the plant
before it bolts. This weevil has reduced stand density in areas
where it has become well established. A leaf feeding beetle
Cassidia rubiiginosa causes considerable damage by skeletonizing
leaves. It is recommended to release more than one type of insect
on a weed since each type may work on different parts of the plant.
Chemical controls:
Cultural controls:
Mechanical controls:
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Musk thistle, like other biennial thistles, thrives on disturbance.
The best management therefore is to minimize disturbance and if it
does occur be certain to revegetate with competitive native
perennial species. Please refer to the revegetation guidelines of
section 4.05 of this plan or contact Pitkin County Land
Management for more information.
The most effective type of mechanical control is to hand pull this
plant prior to flowering. This can be very unrealistic on large
acreage or when the ground is very dry. Another option is to use a
shovel to cut the root below the surface of the soil being careful not
be disturb the soil more than necessary. If this is done prior to
flowering the plant can be left in place after it is cut. If it has
already flowered the plant should be romoved and placed in a bag
and disposed of. Mowing is not effective on this species unless
repeated numerous times throughout the growing season since
Musk thistle will flower and produce seed even after one or two
mowings.
22
OXEYE DAISY
Description:
A rhizomatous perennial.
Comments: A rapidly spreading weed in Pitkin County. Originally planted intentionally
in wildflower mixes, this escaped ornamental is found along the Highway
82 corridor between the Castle and Maroon Creek drainages. It is also
present in the Hunter Creek area.
Biological control:
Chemical controls:
Cultural controls:
None currently available.
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
None available.
Education: The key to oxeye daisy management is to create an awareness among
homeowners, nurseries, landscapers, and landscape architects that oxeye is
a noxious weed and therefore should not be specified in plantings, sold in
nurseries or planted in home gardens or large-scale landscape projects.
Mechanical controls: No information available.
PLUMELESS THISTLE
Description: A biennial, prolific seed producer.
Comments: The most common noxious weed in Pitkin County, it is especially
prevalent in Aspen and Snowmass Village
Biological control:
The same seed head weevil, Rhinocyllus conicus that attacks musk
thistle also feeds on plumeless thistle seeds. Another musk thistle
weevil, Trichosirocalus horridus has been released on plumeless
thistle in Pitkin County. This weevil appears to be ineffective on
plumeless.
Chemical control: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural control:
Mowing is generally not effective on plumeless due to the plant's
capacity for rapid re -growth. Hand cutting is not effective unless
there are repeated follow-up treatments, and should only be
conducted if there is a commitment to follow-up efforts. Plumeless
tends to branch out where it is cut and then re -flower. Work at
Northstar Nature Preserve has indicated that pulling plumeless can
be very effective, especially if done after a light rain. Hand pulling,
23
with a good set of gloves, is preferable to shoveling. Shoveling
disturbs the ground thus creating a potential seedbed for future
infestations.
POISON HEMLOCK
Description:
A biennial.
Comments: One of the most widespread weeds in Pitkin County. Common in East and
West Sopris Creek, Prince Creek, Watson Divide, Woody Creek, and
Lenado. The entire plant is toxic to humans and animals. The plants contain
the intensely poisonous alkaloid coniine and other related alkaloids. Most
poisonings occur because the leaves are mistaken for parsley, the roots for
parsnips, or the seeds for anise. The plant has such an unpleasant taste and
odor that toxic quantities are seldom consumed. If not lethal, recovery
occurs within a few days. Symptoms of poisoning are a burning sensation
in the mouth and throat, nervousness, trembling, incoordination of body
movements, dilation of pupils, muscular weakness, coldness of
extremities, weakened and slowed heartbeat, convulsions, and coma.
Death occurs through respiratory paralysis. There was a case of hemlock
ingestion by local schoolchildren a few years ago. One of their teachers
told the children that the plant was a wild carrot and that they could blow
on it like a whistle. They did and subsequently took ill. The local hospital
called our staff to verify that the plant was hemlock (it was). The hospital
prescribed an antidote and the children recovered.
Biological controls:
Chemical controls:
Cultural controls:
Mechanical controls:
A defoliating moth Agonopterix alstroemeriana, forms
conspicuous leaf rolls.
Often herbicides increase the palatability of plants by affecting the
sugar content. Therefore exercise caution when grazing treated
areas until plants are dried brown or dead. For additional
information contact your local city, county or town natural resource
office. (See section VII for phone numbers.)
Constantly monitor for new infestations. Reseeding of disturbed
sites with fast growing native grasses may competitively inhibit
hemlock. Maintain range and pasture in good condition.
Mowing of pastures before seed heads are formed will effectively
reduce hemlock stands.
24
PURPLE LOOSESTRIFE
Description: An introduced perennial. This escaped ornamental is also a prolific seed
producer, able to produce over 10,000 seeds per square yard.
Comments: At this time the plant is found occasionally in Pitkin County in horticultural
settings. We have not seen evidence that it has spread to native habitat,
however it should be a future concern. The US Fish and Wildlife Service
and the Colorado Division of Wildlife are extremely alarmed about the
proliferation of purple loosestrife in wetland and riparian habitats.
Biological controls: Biological control may eventually bring weed populations under
control, but it will not eliminate or prevent the spread of noxious
weeds. A survey of loosestrife populations in Europe has resulted in
the selection of five insects which may have potential as
biocontrols. Three of these species have completed initial screening
tests conducted by the International Institute of Biological Control
in Switzerland, and one, Hylobius transverovittatus, a root mining
weevil which attacks the vascular tissue of the plant, was
subsequently released in New York in 1991.
Chemical controls: Chemical control has been effective. The choice of chemicals
depends on the location of the infestation. Since most purple
loosestrife infestations are in wetland or aquatic habitats, herbicide
choices are limited. Before herbicides are utilized in a
riparian/wetland situation, all other possible management
alternatives should be investigated. Herbicides should be used only
as a last resort and with extreme caution in wetlands or riparian
areas. For additional information contact your local city, county or
town natural resource office. (See section VII for phone numbers.)
Cultural controls: None available.
Mechanical controls: Mechanical methods include hand pulling, mowing, and flooding.
Hand pulling is effective when infestations are detected early. The
root system must be completely removed, since the root sections
can sprout and form new plants. For this reason hand pulling is only
effective on small plants.
Education: The key to purple loosestrife management and other escaped ornamentals
is to create an awareness among homeowners, nurseries, landscapers, and
landscape architects that purple loosestrife is a noxious weed and therefore
should not be specified in plantings, sold in nurseries or planted in home
gardens or large-scale landscape projects.
25
RUSSIAN KNAPWEED
Description:
A perennial with an extensive underground root system.
Comments: This weed is very common in Eagle and Garfield counties. At this time,
there are very few recorded infestations of Russian knapweed in Pitkin
County. Scattered, small patches may be found along State Highway 133
and along Upper Snowmass Creek Road.
Like other creeping perennials, the key to Russian knapweed control is to
stress the weed and cause it to expend nutrient stores in its root system. An
integrated management plan should be developed that places continual
stress on the weed. Currently, the best management plan includes cultural
control combined with mechanical andlor chemical control techniques. A
single control strategy, such as mowing or an herbicide, usually is not
sufficient. The plant is toxic to horses, however they must consume it over
a period of time before poisoning will occur. Once poisoning occurs horses
are unable to chew and advance food to the back of their mouths,
swallowing is impaired and horses may drink only if they immerse their
head in water far enough to get water to the back of their mouths.
Biological control:
Chemical controls:
Cultural controls:
None currently available.
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Russian knapweed tends to form monocultures by eliminating other
plants. Therefore, sowing desirable plant species is necessary after
the weed is controlled. Research indicates that the native grasses,
streambank wheatgrass and thickspike wheatgrass will establish in
an area after Russian knapweed is suppressed with herbicides. If
the Russian knapweed stand is not too old and grasses are still
present, stimulating grass growth by irrigation (where possible)
should increase grass competition with knapweed and keep it under
continual stress.
Mechanical controls: Repeated mowing combined with herbicide applications will
gradually stress the plant.
SCENTLESS CHAMOMILE
Description:
Comments:
An annual.
A rapidly spreading weed in Pitkin County, very common along the
Highway 82 corridor and throughout the City of Aspen.
26
Biological controls:
Chemical controls:
Cultural controls:
Mechanical controls:
None currently available
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Re -seed disturbed areas with fast growing native grasses.
Mowing should occur early and often with successive mowing
lower than the previous. Plants should be cut before the first
flowers are fully formed. Scentless chamomile will form new
flowers below the cutting height of the swather or mower. Hand
pulling is effective in preventing the spread into new areas. This
method is limited to small infestations. Once plants are pulled, they
should be placed in plastic bags and disposed of properly.
Education: The key to scentless chamomile management and other escaped
ornamentals is to create an awareness among homeowners, nurseries,
landscapers, and landscape architects that scentless chamomile is a noxious
weed and therefore should not be specified in plantings, sold in nurseries
or planted in home gardens or large-scale landscape projects.
SCOTCH THISTLE
Description: A biennial.
Comments: Very rare in Pitkin County. A few plants located on the hillside behind
Centennial, also a small infestation along Capitol Creek Road. A few
infestations are found in the Town of Snowmass Village.
Biological controls: None currently available.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls: Reseeding of disturbed sites with fast growing native grasses.
Mechanical controls: Digging the plant at the rosette stage is effective.
SPOTTED KNAPWEED
Description: A short-lived, non -creeping perennial that reproduces from seed and forms
a new shoot each year from a taproot.
Comments: One of the most invasive, aggressive weeds to plague the western United
States. Very rare in Pitkin County, the largest infestation is found at the
base of Independence Pass along State Highway 82 above Tagerts Lake. It
is imperative that this infestation be monitored yearly and treated as
needed. This infestation must not be allowed to spread in the fragile sub -
alpine ecosystem.
27
Biological controls:
Chemical controls:
Cultural control:
The seedhead flies Urophora affinis and Urophora quadrifasciata
have been released in many Front Range counties. These insects
cause plants to produce fewer viable seeds and abort terminal or
lateral flowers. Root feeding insects may have more of a
detrimental effect on knapweed populations than seed feeding
insects. Larvae of the yellow winged knapweed moth feed in the
roots of both knapweed species.
For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
If desirable grass competition is evident in spotted knapweed
stands, judicious herbicide application that does not injure grasses
may release them to compete effectively with the weeds. Irrigation
may help stimulate grass competition in these cases. Seeding
suitable perennial native grasses is necessary to prevent weed re -
invasion.
Mechanical controls: None available.
YELLOW TOADFLAX
Description:
Comment:
An escaped ornamental perennial reproducing by seed and rootstalk.
Fairly common in the Ashcroft area of Castle Creek. Also found in the
Frying Pan drainage.
Biological controls: One insect species Calophasia lunula a defoliating moth has been
released on yellow toadflax. It may defoliate up to 20 percent of the
leaves.
Chemical controls: For additional information contact your local city, county or town
natural resource office. (See section VII for phone numbers.)
Cultural controls:
Attempt to maintain competitive communities of desirable species.
Re -seed any open ground with native, perennial grasses to prevent
invasion by other weed species.
Mechanical controls: Digging and pulling where feasible can provide effective control of
toadflax if conducted annually for 10 to 15 years.
Education:
The key to yellow toadflax management and other escaped
ornamentals is to create an awareness among homeowners,
nurseries, landscapers, and landscape architects that yellow
toadflax is a noxious weed and therefore should not be specified in
plantings, sold in nurseries or planted in home gardens or large-
scale landscape projects.
28
SECTION III
GEOGRAPHICAL OVERVIEW OF AREAS OF INFESTATION
IN PITKIN COUNTY
3.01 Overview:
Pitkin County was systematically mapped for noxious weeds in 1990, 1994, and 1997.
During the course of fieldwork, new infestations were noted and recorded. The 1994
mapping effort utilized a hand-held Geographical Positioning Unit (GPS) focusing on
county roadsides. In 1997 the emphasis was on identifying property owners who had large
infestations of plumeless thistle. The work done in 1997 will provide a database for
enforcement and education efforts in the future.
This section will provide the casual observer with a thumbnail sketch of the current status
of noxious weed infestations in Pitkin County. This section, in general terms, will discuss
county lands, RFRHA, state and federal lands, municipalities, and private lands.
The County has adopted an "early detection, early treatment" philosophy. Early detection
is identifying and documenting newly introduced weed species into an area. Early
treatment is the follow-up that could possibly eradicate new infestations.
This section will serve as a reference point for "early detection and early treatment" and
will emphasize areas that have new emerging infestations of weed species.
3.02 County Land:
County property is categorized by: Roads; Open Space and Trails and other property;
Airport; Solid Waste Center; and county building grounds. The Plan also addresses
Roaring Fork Railroad Holding Authority (RFRHA) property.
Roads
Pitkin County has about 286 miles of roadsides. It has been the County's philosophy to
minimize the use of herbicides, and thus the impacts on desirable vegetation, by
selectively spot treating noxious weeds with a handgun from a truck -mounted spray unit.
In comparison, most counties perform roadside vegetation utilizing broadcast and blanket
applications of herbicides. This is more effective, in terms of weed control, however this
method must also be measured in terms of environmental impacts. The selective spot
treatment method is 2-3 times slower than the broadcast method.
Most roadsides in the county are lightly to moderately infested with plumeless thistle. The
1987 Pitkin County Weed Control Manual states that the county roads "are estimated to
be 80% infested". Staff would estimate that there has been a reduction in infested
roadsides to about 20% in the last 10 years.
Weed treatment starts every year on the roads located in the northwestern portion of the
29
county where the elevations are lower and the growing season starts earlier. Generally
treatment in these areas is in late April or early May. Ideally, each road in the county
should be monitored and treated twice during the growing season.
Listed below is a brief overview of the current weed situation on the major roads of Pitkin
County. Most roads listed are defined as being "moderate to high service level roads" in
the 1997 Pitkin County Road Management Plan. This overview is not intended to be a
comprehensive noxious weed survey of the county's roads, but rather to provide the reader
with a summary of the major weed problems on the most highly used roads, and to also
list infestations of new weeds. These roads are listed below:
TABLE 3.02(a)
ROADS
PRIMARY WEEDS
NEW WEEDS
Thompson Creek
Musk thistle (moderate)
Dalmatian toadflax
Coal Creek
Musk thistle (moderate); Yellow toadflax
(light)
Russian knapweed
Prince Creek
Plumeless thistle (moderate);
Houndstongue (moderate); Canada thistle
(moderate)
Dame's rocket
W. Sopris Creek
Poison hemlock (moderate); Houndstongue
(light); Canada thistle (light); Plumeless
thistle (moderate)
Common tansy
Emma
Common tansy (heavy); Canada thistle (light);
Plumeless thistle (light)
E. Sopris
Plumeless thistle (light); Houndstongue (light);
Poison hemlock (moderate); Hoary cress (light)
Lower Snowmass
Plumeless thistle (heavy)
*note - This road has several residents who prefer to
have no herbicide use along the roadside.
Upper Snowmass
Plumeless thistle (light); Canada thistle (light);
Common tansy (light); Hoary cress (moderate)
Wild caraway
Russian knapweed
Toadflax(hybrid)
Capitol Creek
Plumeless thistle (light); Houndstongue
(moderate) *note - Dalmatian toadflax and Scotch
thistle located close to Monastery Road.
Dalmatian toadflax
Scotch thistle
Watson Divide
Plumeless thistle (light); Poison hemlock (light)
Lower River
Musk thistle (light) Poison hemlock (light)
Plumeless thistle (moderate)
Diffuse knapweed
30
Upper River
Plumeless thistle (moderate);
Leafy spurge (moderate)
Russian knapweed
Woody Creek
Plumeless thistle (moderate); Leafy spurge
(moderate); Canada thistle (scattered); Poison
hemlock (moderate); Musk thistle (light)
note - very small patch of diffuse knapweed along lower
Woody Creek Rd.; Russian knapweed is located near Lenado
Diffuse knapweed
Russian knapweed
McLain Flats
Plumeless thistle (light)
Leafy spurge
Brush Creek
Plumeless thistle (heavy); Canada thistle (light);
note - Dame's rocket planted ornamentally by the
Snowmass Village entrance sign below the Rodeo grounds.
Dame's rocket
Owl Creek
Plumeless thistle (heavy); Canada thistle
(moderate)
Maroon Creek
Plumeless thistle (light); Common burdock (light)
Castle Creek
Plumeless thistle (light); Yellow toadflax (light)
note - Primary infestation of yellow toadflax located near
Ashcroft, use of herbicides is not accepted by local community.
Leafy spurge
Frying Pan
Musk thistle (moderate); Plumeless thistle
(moderate); Yellow toadflax (light).
3.03 Open Space & Trails and Other County Property:
For the purposes of the weed management plan, we will not make distinctions between
lands managed by Pitkin County and those managed by Pitkin County Open Space &
Trails. This section will not attempt to list all parcels, trails, and properties owned by the
County, but instead will focus on the major properties and provide a general overview of
the current weed situation on those areas. New invasive weeds will also be noted.
TABLE 3.03(a)
TRAILS
PRIMARY WEEDS
NEW WEEDS
ABC
Plumeless thistle (light)
Chamomile
Oxeye daisy
BasaltiSnowmass
Plumeless thistle (light)
Dalmatian toadflax
East of Aspen
Plumeless thistle (moderate);
Chamomile (moderate); Yellow toadflax (light);
Houndstongue (light); Canada thistle (light)
Dame's rocket
31
Emma Rd.
Plumeless thistle (heavy); Common tansy (light)
High School
Plumeless thistle (heavy)
Leafy spurge
Chamomile
Hunter Creek
Plumeless thistle (light);
Common tansy (moderate)
Chamomile
Owl Creek
Plumeless thistle (moderate);
Canada thistle (moderate)
Rio Grande
Plumeless thistle (heavy); Houndstongue (light);
Yellow toadflax (scattered); Leafy spurge
(heavy from Jaffee Park to Tavern)
*note - Leafy spurge located at west entrance to City
portion of Rio Grande Trail
Dalmatian toadflax
(Jaffee Park)
TABLE 3.03(b)
PROPERTY
PRIMARY WEEDS
NEW WEEDS
Airport Ranch
Plumeless thistle (light); Houndstongue
(moderate)
Wild caraway
Arbaney Kittle
Plumeless thistle (scattered)
Goats rue
Aspen Mass
Plumeless thistle (heavy); Leafy spurge
(moderate)
Diffuse knapweed
Jaffee Park
Plumeless thistle (heavy); Chamomile (moderate);
Leafy spurge (heavy); Yellow toadflax (light)
Dalmation toadflax
Moore
Plumeless thistle (heavy); Houndstongue
(moderate)
Chamomile
Northstar
Plumeless thistle (moderate);
Canada thistle (moderate); Yellow toadflax
(light); Houndstongue (moderate)
Sulfur cinquefoil
Chamomile
Redstone Park
Yellow toadflax (scattered)
3.04 Airport:
The 1987 Pitkin County Weed Control Manual estimates that the Airport has 100 acres of
infested land. That has been reduced to about 40 acres in 1997. The worst areas are the
parcels north of the runway, the west side of the airport where the soil material has been
deposited, and the old hay field by the cabin. The south side of the property, adjacent to
Owl Creek Road, has had its thistle population reduced by about 80% since 1990. Radar
32
Road will continue to need annual monitoring and treatment. It should be noted that there
is a small patch of Russian knapweed along the lower portion of Radar Road. The Airport
Ranch property has severe plumeless thistle and houndstongue problems around the old
corrals and equipment storage areas. The pasture areas are generally in good shape but
will require annual spot treatments.
3.05 Solid Waste Center:
Weed populations at the Solid Waste Center, located at the Pitkin County Landfill, have
been significantly reduced in the last ten years, however this area should continue to be a
priority for weed treatment as it is a center of activity. Particular attention should be given
to the area around the composting sites. The compost may serve as a vehicle for weed seed
transportation. Scentless chamomile is starting to move into the area, and plumeless thistle
continues to be a problem.
Other priorities include:
The Road & Bridge material storage area.
The Shooting Range.
All roadsides.
The primary problem weed is plumeless thistle. There is also a common burdock problem
below the cedars on the entrance road. Occasionally a leafy spurge plant shows up, those
have been treated when detected.
3.06 The Roaring Fork Railroad Holding Authority (RFRHA):
There are 23 miles of railroad right-of-way in Pitkin County. The responsibility for weed
management of this property now rests with RFRHA.
Plumeless thistle, musk thistle, houndstongue, and common tansy are the main problems
on the lower end, with plumeless, mullein, and leafy spurge infesting the Woody Creek
area.
The County will assist RFRHA in the development of a weed management plan.
3.07 State Lands:
Since 1991, Pitkin County has received funding from CDOT to manage noxious weeds on
State Highway 133 and 82. This has been approximately $7,500 per year. From 1991-
1994, land management crews performed the treatment work. Since 1995 the County has
administered the funds and hired a subcontractor to do the work. Occasionally land
management crews have supplemented the subcontractors' work on an as -needed basis.
State Hwy 82
The 55 miles of State Highway 82 in Pitkin County are estimated to be 10% infested. This
is a reduction from the estimates in the 1987 Pitkin County Weed Control Manual, which
put the infested percentage at 50%. The major weeds on Hwy 82 are as follows:
33
TABLE 3.07(a)
AREA
PRIMARY WEEDS
NEW WEEDS
Emma/Basalt
Plumeless thistle
Common tansy
Basalt/
Old Snowmass
Plumeless thistle
Musk thistle; Canada thistle
Dame's rocket
Old Snowmass/
Plumeless thistle
St. John's wort;
Yellow toadflax;
Perennial pepperweed
Watson/
Brush Creek
Plumeless thistle
Brush Creek/
Airport
Plumeless thistle
Canada thistle
Oxeye daisy
Scentless chamomile
Airport/Aspen
Plumeless thistle; Common tansy
Oxeye daisy; Scentless chamomile
Dame's rocket
Northstar/
Independence Pass
Plumeless thistle
Houndstongue; Spotted knapweed
Scentless chamomile
State Hwy 133
The 20 miles of State Highway 133 in Pitkin County are estimated to be 15% infested.
Musk thistle is the dominant weed along Hwy 133. In any given year there are six to
twelve patches of Russian knapweed found along Hwy 133. These knapweed patches
should be continually monitored and treated on an as -needed basis. Oxeye daisy is
becoming a problem along Hwy 133 near the road to Marble. This is in Gunnison County,
but poses a threat to lands within Pitkin County.
34
TABLE 3.07(b)
AREA ON
HWY 133
PRIMARY WEEDS
NEW WEEDS
Garco line/BRB
Musk thistle
Russian knapweed
Plumeless thistle
BRB/Redstone
Musk thistle
Plumeless thistle
Redstone/
McClure Pass
Oxeye daisy
Yellow toadflax
Division of Minerals and Geology (Coal Basin Mine reclamation project of private and
public land administered by Division of Minerals and Geology).
The Division, in partnership with the County, the Office of Surface Mining, and the US
Forest Service received a Noxious Weed Control Grant from the Colorado Department of
Agriculture in 1998 for treatment of 20 acres of solidly infested land at Coal Basin. A
treatment strategy was implemented in July of 1998. The Division reports that the project
was successful, there is a carryover of funds and that there will be a follow-up treatment
in 1999.
3.08 Federal Land:
White River National Forest
The Forest has extensively mapped and inventoried its land in Pitkin County. That
information is available through the White River National Forest or the Pitkin County
Land Manager's office.
Bureau of Land Management
The Bureau of Land Management has been mapping infestations of Canada thistle,
plumeless thistle and houndstounge in the Prince Creek drainage and the Crown area.
Insects were released as many as 10 years ago on Canada thistle in the Prince Creek
enclosure. The release had little noticeable result, mainly due to low survival success of
the biological agents. BLM and Pitkin County have a cooperative agreement that has been
utilized for about 5 years. BLM has contributed funds to Pitkin County for prevention and
control activities and is willing to continue this agreement in the future. The weed
infestation in the area is moderate and management efforts should continue. The BLM has
had more funding for its weed management program in the last 3 years and expects it to
continue at the higher level into the near future.
35
Bureau of Reclamation
Official surveys have not been done at this time, however reports indicate that over 60
acres of USFS/Bureau of Reclamation land are infested with plumeless thistle.
3.09 Municipalities:
City of Aspen
County Land Management staff mapped and inventoried city trails in 1998. This
information is recorded in the County Assessor's Global Information System (GIS).
Responsibility for noxious weed management within the city of Aspen falls under the
jurisdiction of the Aspen Parks Department. The Parks Department has had a treatment
program in place for the last few years on its parks, open space, and trails. The Department
has managed to significantly reduce thistle populations on its property in the last five
years. The escaped ornamentals (common tansy, chamomile, and oxeye daisy) are rapidly
becoming a problem on city -owned property. The Aspen Golf Course berm has a large
infestation of dame's rocket, one of the most extensive in Pitkin County. Common tansy
is now a problem along the trail in front of the golf course.
There are two areas that need improvement:
1. Weeds on private land located within the city limits. It is recommended that the City
Council adopt this weed management plan and empower a city department with
enforcement authority.
2. Roadside weed management. Currently there isn't a program in place that addresses
noxious weed management on city street rights -of -way. Again, it is recommended that
the City Council implement a roadside weed management program similar to the
county's.
Town of Snowmass Village
The Town's Building and Planning Department, through its landscape planner,
coordinates noxious weed programs within the town limits. They have been fairly
aggressive in treating plumeless thistle on major thoroughfares within the town in the past
five years. Poison hemlock remains a problem around the perimeter of the golf course and
along upper Brush Creek.
There are two areas that need improvement:
1. Intentional planting of invasive ornamentals. Dame's rocket has been used in landscape
situations, flower gardens, and along pathways and trails. It has now escaped its
boundaries and has become a true, invasive, aggressive weed with the potential to
displace native plants. It is recommended that the Town cease the intentional planting
of this plant and approach dame's rocket management in a similar fashion to their thistle
management program.
36
2. Weed enforcement on private lands within town limits.
Town of Basalt
Basalt is located in both Pitkin and Eagle counties. It is recommended that Basalt adopt
both counties' noxious weed lists. Most noxious weed issues are addressed by the Town's
Public Works Department. The most common weeds in Basalt are plumeless thistle and
common tansy. Musk thistle is prevalent along the Frying Pan. Basalt has implemented a
chemical use plan. Prior to any herbicide treatment within the Town, the plan must be
submitted to and approved by the Town Board.
Areas to work on:
1. Intentional planting of invasive ornamentals.
2. Weed enforcement on private lands within town limits.
PITKIN COUNTY, ASPEN, SNOWMASS VILLAGE, AND BASALT NEED TO HAVE
DESIGNATED DEPARTMENTS WITHIN THEIR JURISDICTIONS TO DEAL WITH
THE WEED ENFORCEMENT ISSUE.
37
SECTION IV
PLAN OF WORK
4.01 Objectives and Goals:
• Implement "Title 35 Article 5.5, The Colorado Weed Management Act."
• Educate the public concerning weed management issues.
• Generate public support for the weed management program.
• Foster a spirit of cooperation among federal, state and local governmental agencies
and private landowners.
• Work with other government agencies and departments to institute "Best
Management Practices" and/or land use regulations that stress the importance of
prevention as a weed management tool.
• Promote and use integrated management techniques.
• Establish and maintain healthy plant communities with native or beneficial
vegetation.
• Restore and maintain desirable plant communities and healthy ecosystems in
Pitkin County.
• Stop the spread of noxious weeds to uninfested lands.
• Contain heavily weed -infested areas.
4.02 Prevention and Detection:
Prevention is the highest priority weed management technique on non -infested lands.
From government officials, land managers, farmers, ranchers, and the general public there
is growing recognition that protecting and encouraging weed -free plant communities is
the most economical and efficient land management practice. The benefits are obvious.
Weed -free plant communities:
• Provide essential wildlife habitat and forage.
• Save ranchers and farmers many billions of dollars in labor costs and
lost production.
• Ensure aesthetic and recreational qualities of an area.
• Prevent soil erosion, plus improve water quality.
The spread of noxious weeds is most likely to occur where soil has been disturbed either
through human activities such as road and trail cuts, construction sites, the spread of
gravel, road fill and topsoil contaminated with noxious weed seed, overgrazing or by
natural events such as fire, avalanches, mudslides, flooding. Where land is disturbed there
is opportunity for noxious weeds.
Exotic plants and seeds such as oxeye daisy, dame's rocket, purple loosestrife, scentless
chamomile and toadflax escape through our yards and gardens. Since they are attractive
and establish themselves quickly they are popular with landscapers and gardeners for
ornamental planting and may be purchased through nurseries. They have the same ability
38
to dominate and spread, however, as other better known noxious weeds.
Still other known methods of weed introduction include:
• Contaminated seed, feed grain, hay, straw, and mulch.
• Movement of contaminated equipment, cars, bikes, etc. across uncontaminated
lands.
• Animal fur, fleece, human clothing.
• Dried flower arrangements.
Prevention is best accomplished by ensuring that new weed species' seed or vegetative
reproductive plant parts are not introduced into new areas, and by early detection of any
new weed species before they become widespread.
STRATEGIES to prevent the introduction or establishment of noxious weeds in areas not
already infested include:
• Identification and eradication of small, new infestations.
• Continuous monitoring and evaluation to prevent recurrence.
• Identification of existing conditions, disturbances, and activities that represent a
potential threat to native habitat.
• Identification of burgeoning weed species that represent a future threat.
• Timely revegetation and reclamation of disturbed sites using appropriate native
plant species.
• The use of weed free seeds and mulch.
• Countywide promotion of the Colorado Weed Free Hay and Forage program.
• Prioritization of weed management along areas of entry and dispersal.
• Work with local nurseries to discourage the sale of ornamental plants and seed
packets.
PREVENTION WILL ALWAYS BE THE MOST EFFECTIVE NOXIOUS WEED
CONTROL AVAILABLE.
4.03 Education and Awareness:
Education must play a major role in implementing this weed management plan. Groups
targeted for public education include: farmers and ranchers, homeowners' associations,
private citizens, developers, gardeners, landscapers, nurseries, public and private
agencies, recreational users, youth groups and schools.
A partnership of the public and private sectors with awareness of what noxious weeds are
and the problems they cause is essential to maintain or create plant communities that are
free of noxious weeds. Knowledge about how to identify weeds, how and where weeds
are spread, and what it takes to manage weeds is necessary. Continuation and expansion
of current educational programs along with the development of new programs is a priority
of the Pitkin County Noxious Weed Management Plan. This instruction will be provided
by the Pitkin County Land Management Department, or its representative, and other
39
governmental agencies. Workshops will be held throughout the year to provide public
awareness to enhance the following educational opportunities:
• Widespread distribution of informative printed material.
• Promotion of a video on Grassroots.
• Development of an informative website on the Internet.
• Offering weed tours and talks to the public.
• Contacting area nurseries, landscapers, and landscape architects, to emphasize the
problems created by escaped ornamentals.
• Contacting local newspapers with informative articles.
• Distributing weed free seed packets of native species.
WEED MANAGEMENT BEGINS WITH EDUCATION.
4.04 Land Stewardship:
The Colorado Noxious Weed Act stipulates that all property owners use integrated
methods to manage noxious weeds. Weed management is an ongoing challenge, requiring
an Integrated Weed Management approach in which all weed management practices are
considered for use. Most weed species, if detected early, can be managed.
STRAI'bGIES:
• Identify your plants.
• Understand the target weed. Does it reproduce by seed or roots or both?
• Maintain inventory maps.
• Develop a database.
• Develop site specific weed management plans in cooperation with individual
landowners and county and state officials.
• Develop a decision making process that uses site specific information to make
decisions about treatment options.
• Develop a long-term strategy including regular monitoring of treatment areas.
MAINTAINING LAND THAT IS FREE OF WEEDS IS GOOD STEWARDSHIP.
LANDOWNERS WHO DO NOT CONTROL THEIR WEEDS PLACE THEIR
NEIGHBORS' LANDS AT RISK.
4.05 Revegetation and Rehabilitation:
A crucial part of any weed management plan is the reintroduction of native vegetation or
beneficial plants.
Establishing a desirable plant community after noxious weeds have been removed from a
highly infested area requires timely cultivation and reseeding. Since the seeds from
noxious weeds may lay dormant for many years, removing all visible signs of the noxious
weeds does not ensure against their return. Revegetation can help prevent the germination
of weed seeds. It is important to inspect the land regularly to identify and treat small, new
40
infestations. For proper reclamation, managed irrigation of dry areas, fertilization, and
reseeding are essential to establish plant communities.
Weed -free seeds of native Colorado grasses, wildflowers or plant species appropriate to
the site may be purchased, but the best source for seeds is from native species that grow
in the immediate vicinity of the infestation. They will be best adapted to local conditions
and will help maintain local genetic viability. Using native plants or seeds to reclaim
disturbed land reduces degradation of native ecosystems, reduces the need for herbicides
and conserves water resources. Native plants will provide a broad biological diversity and
help keep Colorado looking like Colorado with a unique regional landscape that sets us
apart from other areas of the country.
For more information please consult the Pitkin County Landscaping & Revegetation
Guidelines available at Pitkin County Public Works.
4.05(a) Recommended Plant List
A. TREES
Creek/River Bottoms
Colorado Blue Spruce
Douglas Fir
Narrowleaf Cottonwood
Aspen
Sage Flats
Scrub Oak
Irrigation Ditches
Narrowleaf Cottonwood
Douglas Fir
North Slope
Douglas Fir
Ponderosa Pine
Lodgepole Pine
Aspen
Ponderosa Pine
Lodgepole Pine
Rocky Mountain Maple
Western Juniper
Aspen
South Slope:
Western Juniper
Pinion Pine
Scrub Oak
B. SHRUBS
Amelanchier alnifolia — Serviceberry
Artemesia frigida — Fringed Sage
Artemesia tridentata `Vaseyana' — Mountain Sage
Cercocarpus mountanus — Mountain Mahogany
Purshia tridentata — Antelope bitterbrush
41
C. SEEDING
The following seed mix has been formulated specifically for revegetation work in
Pitkin County. Any deviation from this recommendation must be authorized by
Pitkin County Public Works Staff.
Native Seed Mix
Common Name
Western Wheatgrass
Mountain Brome
Slender Wheatgrass
Thickspike Wheatgrass
Indian Ricegrass
Blue Flax
Rocky Mtn. Penstemon
Scientific Name
Agropyron
Bromus marginatus
Agropyron trachycaulum
Agropyron dasystachum
Oryzopsis hymenoides
Linum lewisii
Penstemon strictus
Total lbs. per live seed/acre (broadcast)
Pure Live Seed
LBS/Acre
10
6
6
6
4
.5
1
33.5
Seeding Selection
Topsoil for any projects must be stored on site and replaced on the area to be
reclaimed. No topsoil will be brought onto site without prior clearance from Pitkin
County Public Works staff. No fertilizer is to be applied to the revegetated area. The
disturbed area is to be protected by hydromulch, to be applied after the seed is
broadcast. The preferred mulch shall be 100% virgin wood fiber with tackifier to be
applied at a rate of 1500 lbs. per acre. Any hay or straw used as a mulch must be
certified by the Colorado Department of Agriculture as weed free seed.
STRATEGIES:
• Study all vegetation in the area and surrounding areas.
• Preserve plant species native to Colorado.
• Test the soil for pH balance. Try to retain and utilize as much on -site topsoil as
possible.
• Select a predominant species that is appropriate to the .site. Then choose a few
complimentary species to provide a balanced plant community.
• Choose plants that are healthy, vigorous and pest free.
• Use weed -free seeds. Use non -hybrid seeds. Avoid commercial seedpackets
containing exotic plant species.
• Choose plants that are horticulturally appropriate i.e. plant species that are
adaptable to climate, soil and topographical conditions of the designated area.
• Consider the use of water, its availability and the vegetative requirements.
• To landscape for wildlife, choose native plants that provide cover, forage, browse,
seeds for birds and rodents, and shade.
• Be site specific: revegetation strategies may vary for small lots, farms, ranches or
construction sites.
42
• Establish a vegetative cover
self -regeneration.
• Stabilize the surface.
• Limit nursery production of
enhance healthy ecosystems.
that is diverse, effective and long lasting, capable of
non-native vegetation to protect, maintain, restore or
4.06 Native Plants:
More than 10% of Colorado's native plant species have been displaced by non-native
weeds. Exotic plants have arrived from other countries without the natural enemies that
keep them in check in their country of origin. These new plants are typically very
aggressive and have the ability to dominate many sites and overwhelm the existing native
plant communities. Wildlife habitat deteriorates, water quality diminishes, erosion
increases, nutrient cycling and filtration are altered, and recreation values are degraded.
Native plants are an integral part of all healthy ecosystems. They provide genetic material
that strengthens our major food crops, native medicines, native products, and natural
beauty. They provide food and shelter to animals. To protect these plants, we must protect
habitats.
Vegetation varies dramatically in Pitkin County with changes in elevation, slope, water
resource, temperature and soil type. To determine the appropriate plants to use for
revegetation one must study the land affected and the surrounding area. A community may
be defined as all the plants and animals living in a particular area. Plant communities are
usually named for their most prominent and/or abundant members. Community
classifications can range from general descriptions such as "grassland" or "forest" to more
detailed designations which include species names. An example of this would be a "pinon
pine juniper woodland." The term natural communities refers to plant species and
communities which occurred in Colorado before European settlement and which retain the
capability of maintaining themselves without human interference.
The Colorado State Parks Natural Areas Program has recently published the Native Plant
Revegetation Guide for Colorado. This is a source book developed to assist land managers
with one of the most critical and often confusing tasks —restoring or revegetating
disturbed areas using plants native to Colorado. Pitkin County recommends that this
guide be used as a tool in revegetation projects.
Most land within Pitkin County falls in the following plant communities:
• Grasslands
• Shrublands
• Woodlands
• Forests
• Alpine Tundras
• Wetland/Riparian
43
Within these broad categories are more specific, detailed designations. Under these
designations, plants are listed as either grasses, forbs, or trees and shrubs. The Guide lists
the appropriate plants in each category for that particular plant community. Upon request
staff will provide interested parties with a copy of pertinent information from the Guide.
NATIVE PLANTS AND WILDFLOWERS HELP DEFINE OUR PLACE IN THE
NATURAL WORLD.
4.07 Mapping and Inventory:
Mapping is a valuable tool in integrated weed management. As such, the Weed Manager
will establish and maintain visual maps of past and present infestations of noxious weeds
on county land. This will provide a graphic representation of weed management progress
and needs.
The primary goal of mapping will be to record the noxious weed species present, areas
infested, density of infestations, and other site factors pertinent to successfully managing
the infestation.
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SECTION V
ENFORCEMENT
5.01 Compliance: Private Lands: Management of Noxious Weeds
A. Inspection.
(1) Pitkin County, through its delegates, agents, and employees, shall have the right to
enter upon any premises, lands, or places, whether public or private, during reasonable
business hours for the purpose of inspecting for the existence of noxious weed
infestations, when at least one of the following circumstances has occurred: (a) The
landowner has requested an inspection; (b) A neighboring landowner or occupant has
reported a suspected noxious weed infestation and requested an inspection; or (c) An
authorized agent of the local government has made a visual observation from a public
right-of-way or area and has reason to believe that a noxious weed infestation exists.
(2) (a) No entry upon any premises, lands, or places shall be permitted until the
landowner or occupant has been notified by certified mail that such inspection is
pending. Where possible, inspections shall be scheduled and conducted with the
concurrence of the landowner or occupant. (b) If after receiving notice that an
inspection is pending the landowner or occupant denies access to the inspector of the
local governing body, the inspector may seek an inspection warrant issued by a
municipal, county, or district court having jurisdiction over the land. The court shall
issue an inspection warrant upon presentation by the local governing body, through its
agent or employee, of an affidavit stating: The information which gives the inspector
reasonable cause to believe that any provision of this article is being or has been
violated; that the occupant or landowner has denied access to the inspector; and a
general description of the location of the affected land. No landowner or occupant
shall deny access to such land when presented with an inspection warrant.
B. Management.
(1) If following inspection pursuant to section 5.01(A) land is found to contain
designated undesirable plants, the landowner shall be given written notice, personally
or by certified mail. The notice shall name the undesirable plants, identify the location
of the plants, advise the landowner to control the undesirable plants, and specify the
best available control methods of integrated management. The notice shall include an
offer to consult with the landowner in the development of a management plan,
including a plan for the control of undesirable plants on the land. The notice also shall
state that the landowner shall, within a reasonable time not to exceed 10 days, either
(I) comply with the terms of the notification, (II) acknowledge the terms of the
notification and submit an acceptable plan and schedule for the completion of the plan
for compliance; or (III) request an arbitration panel to determine the final management
plan.
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(2) If the landowner chooses action option I, the Pitkin County Land Management
Department, or its representative, will re -inspect the land to confirm compliance.
(3) If the landowner chooses action option II, the Pitkin County Land Management
Department, or its representative, will review the proposed weed management plan
and determine its efficacy. If the plan is acceptable, no further action will be taken
except to monitor compliance, including re -inspection.
(4) If the landowner chooses action option III, an arbitration panel will be selected by
the Board of County Commissioners, in accordance with CRS 35-5.5-109(4)(b). The
arbitration panel shall be comprised of a weed management specialist or weed
scientist, a landowner of similar land in the same county, and a third panel member
chosen by agreement of the first two panel members. The landowner or occupant shall
be entitled to challenge any one member of the panel, and the local governing body
shall name a new panel member from the same category. The decision of the
arbitration panel shall be final. A hearing shall be set for a time and date as soon as
practical after the panel is complete. The Pitkin County Land Management
Department, or its representative, shall give written notice, personally or by mail, of
the hearing to any complaintant. The landowner is entitled to appear before the panel,
individually and/or by representative, as is any complaintant. The arbitration panel
will be required to determine the final management plan not more than two calendar
weeks after the hearing is completed. In the event of non-compliance with any
management plan, in addition to remedies set forth in paragraph 5.01C. The arbitration
panel shall have the ability to award cost of the arbitration to the prevailing party
including arbitration panel fees and expenses. These fees and expenses may include,
but are not limited to, salary, wages, travel, and meal per deim.
C. Failure to Comply.
1. Public Nuisance.
If the landowner fails to comply with the notice to control the designated
undesirable plants, fails to submit an acceptable management plan, fails to
comply with an accepted management plan, or fails to comply with a
management plan as determined by the arbitration panel, the Board of County
Commissioners, at a public hearing at least 10 days after notice thereof to the
property owner, may declare the infested property a public nuisance for which
the remedies for abatement of a public nuisance shall be available as provided
in C.R.S. 35-5.5-113. Once declared, such nuisances are subject to all laws and
remedies relating to the prevention and abatement of nuisances.
2. Other remedies.
In addition to, or as an alternative to the nuisance remedy, Pitkin County may
compel management of the weeds in the following manner: The Pitkin County
Land Management Department, or its representative, shall give written notice
of a hearing before the Board of County Commissioners to the landowner by
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personal delivery or by certified mail which will include the date and time of
the hearing, 10 days prior to the hearing date. The notice will include (i)
description of the land, (ii) name of the undesirable plants and their location(s)
on the land, (iii) date the Pitkin County Land Management Department, or its
representative, will perform weed control on the land, (iv) method of control
to be applied, (v) a statement that the land will be assessed the entire cost of
the weed control plus 20% surcharge for the cost of inspection and other
incidental costs, which total will be a lien on the land (or the tract of which it
is a part) until paid, and (vi) a statement should the landowner refuse
admission to the land for application of the weed control, the County will seek
civil and/or criminal penalties and court -enforced abatement of a public
nuisance. Such an assessment under this section shall have priority over all
other liens except general taxes and prior special assessments. Such
assessment may be certified by Pitkin County Land Management to the County
Treasurer and collected and paid over in the same manner as provided for
collection of taxes. Costs of providing for and compelling weed management
shall not be assessed until the level of management called for in the notice or
as developed by the arbitration panel has been successfully achieved.
3. Other Occupants.
Whenever the land is known to the Pitkin County Land Management
Department, or its representative, to be occupied by someone other than the
record owner, written notices also shall be given to the occupant, and the
occupant shall be informed that C.R.S. 35-5.5-109 and this regulation imposes
on occupants the same responsibilities for undesirable plant control as it
imposes on landowners.
4. Notice.
Whenever notice is given by mail, it shall be deemed given when deposited in
a regular depositary of the United States Postal Service, postage prepaid.
Notice to landowners shall be mailed to the last known address as shown in the
County's Assessment Roll unless the landowner has provided the Pitkin
County Land Management Department, a different address for notice. Notice
to occupants shall be mailed to the land's physical address unless the occupant
has provided the Pitkin County Land Management Department with a different
address for notice.
5. Condition Precedent.
No private land management shall be compelled without first applying the
same or greater management measures to county land or rights -of -way that are
adjacent to the private property.
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5.02 State Public Lands: Compliance of lands owned by the state of Colorado or its agencies
is governed by C.R.S. 35-5.5-110.
5.03 County Rights -of -Way: It shall be the duty of Pitkin County to confirm that all county
roads, highways, rights -of -way, and any easements appurtenant thereto, are in compliance
with the Colorado Noxious Weed Act and this management plan, and any violations by the
county of this article shall be the financial responsibility of the county.
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SECTION VI
6.01 PLAN EVALUATION
The goal and plan of work in the Pitkin County Noxious Weed Management Plan will be
reviewed and evaluated annually at the January Pitkin County Weed Advisory Board meeting.
Any proposed additions or changes shall be recommended by the Pitkin County Weed Advisory
Board and approved by ordinance by the Board of County Commissioners before becoming final.
The Pitkin County Noxious Weed Management Plan shall be reviewed by the Weed Advisory
Board at least every three years, per CRS 35-5.5-107(4)(a); and the management plan and any
recommended amendments to the plan shall be transmitted to the Board of County
Commissioners for approval, modification, or rejection.
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SECTION VII
RESOURCE DIRECTORY
7.01 Government & Other Agencies
Bureau of Land Management
Glenwood Springs Resource Area
PO Box 1009
Glenwood Springs, CO 81602
(970) 947-2800
City of Aspen Parks Department
130 S. Galena
Aspen, CO 81611
(970) 920-5120
Colorado Department of Agriculture
Eric Lane, State Weed Coordinator
700 Kipling St., Suite 4000
Lakewood, CO 80215-5894
(303) 239-4182
E-Mail: Eric.Lane@ag.state.co.us
Colorado Department of Transportation
Region 3-Maintenance Section No. 2
222 S. 6th St., Room 317
Grand Junction, CO 81501
Phone: (970) 248-7361
Colorado State University
Dept. of Weed Science & Pest Mgmt.
(970) 491-7568
Colorado Weed Management Assc.
PO Box 1910
Granby, CO 80446-1910
(970) 887-1228
E-mail: cwma@rkymtnhi.com
Department of Agriculture Insectary
P.O. Box 400
Palisade, CO 81526
(970) 464-7916
Eagle County Weed Department
PO Box 239
Eagle, CO 81631
(970) 328-8778
Garfield County Vegetation Mgmt.
PO Box 1112
Rifle, Co 81650
(970) 625-3969
Pitkin County Land Management
76 Service Center Road
Aspen, CO 81611
(970) 920-5214
Roaring Fork Railroad Holding Auth.
PO Box 1270
Carbondale, CO 81623
(970) 704-9282
Town of Basalt Public Works
101 Midland
Basalt, CO 81621
(970) 927-4723
Town of Snowmass Village
Building & Planning Department
P.O. Box 5010
Snowmass Village, CO 81615
(970) 923-5524
White River National Forest
PO Box 309
Carbondale, CO 81623
(970) 963-2266
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7.02 Help from the Web
Colorado Weed Management Assc.
http://www.fortnet.org/CWMA
Native Plant Conservation Initiative
http://www.nature.nps.gov/npci/
Bureau of Land Management
http://www.blm.gov./education.html
National Wildlife Federation
http://www.nwf.org
Pesticide Information
http:// 164.159.187.239?NWRSFi1es/Int
ernetresources/Pesticide.html
7.03 BOOKS
Weeds of the West
University of Wyoming Bulletin Room
(307) 766-2115
Colorado Flora, Western Slope
William Weber and Ronald Wittman
Available in most bookstores
Native Plant Revegetation
Guide for Colorado
Colorado Natural Areas Program
Phone: (303) 866-3437
Noxious Weeds, Exotic and Invasive
Plant Management Resources
http://164.159.187.239/NWRSFi1es/In
ernetResources/VVeeds.html
Weed Science Society of America
http://piked2.agn.uic.edu/wssa/
Colorado Natural Heritage Program
http://colostate.edu/Orgs/CNHP
Colorado Natural Areas Program
http://elbert.state.co.us/cnap
Chemical Label Information
http://greenbook.net
Trees and Shrubs of Colorado
By: Jack Carter
Available in most bookstores
Troublesome Weeds of the Rocky
Mountain West
Colorado Weed Management Assoc.
Available through Pitkin County Land
Management
(970) 920-5390
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SECTION VIII
8.01 DEFINITIONS
1. Act —The Colorado Noxious Weed Act, Title 35 C.R.S., Article 5.5 as amended.
2. Adjacent —Having a common boundary that meets or touches at some point.
3. Aggressive —Fast growing, tending to spread quickly.
4. Agriculture —Uses involving the cultivation of land, production of crops, and/or the
keeping of livestock and the preparation of these products for man's use and disposal.
5. Alien Plant —A plant species that is not indigenous to the State of Colorado.
6. Annual —A plant which lasts one growing season, completing it's life cycle from seed to
seed in one year.
7 Biennial —A plant which lives in two calendar years. The first year is usually a vegetative
form, such as a rosette of leaves. The second year the plant grows a flowering shoot, sets
seeds and dies.
8. Biological Management —The use of organisms to disrupt the growth of noxious weeds.
9. Bolt —To flower or produce seeds prematurely or develop a flowering stem from a rosette.
10. Bract —A reduced or modified leaf often surrounding the base of a flower.
11. Browse —Tender shoots, twigs, and leaves of trees and shrubs fit for food for wildlife.
12. Chemical Management —The use of agents or plant growth regulators to disrupt or inhibit
the growth of noxious weeds.
13. Commissioners —Refers to the Pitkin County Board of Commissioners.
14. County —The unincorporated areas of Pitkin County.
15. Cultural Management —Methods or management practices which favor the growth of
desirable plants over noxious weeds, including maintaining optimum fertility and plant
moisture status in an area, planting at optimum density and spatial arrangement in an area,
and planting species most suited to a particular area.
16. Designated Noxious Weed —A non-native, invasive plant or plant parts that is identified
as a threat to native plant communities and included on the Pitkin County Noxious Weed
list.
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17. Desirable Plants —Plants considered to be advantageous and beneficial to the
environmental viability of the county.
18. Escaped Ornamental -A plant originally intended for horticultural or landscape situations
that has escaped its intended boundaries.
19. Exotic Plant —A plant that is not a regular member of the native or natural community in
which it is found.
20. Forb—A broad -leafed, non -woody plant other than grass that dies back to the ground after
each growing season.
21. Forage —Food for animals, especially when taken by browsing or grazing.
22. Herbaceous —Applies to plants of soft texture whose stems die back to the ground after
each growing season; Green and leaf like, not woody.
23. Infestation —To have overrun or inhabit so as to be harmful or bothersome.
• Heavy Infestation —Dense, 25-100 percent canopy cover.
• Moderate Infestation —Widely scattered plants, 5-25 percent canopy cover.
• Light Infestation —Occasional plant per acre, less than 5 percent canopy cover.
24. Integrated Management —The planning and implementation of a coordinated program
utilizing a variety of methods for managing noxious weeds, the purpose of which is to
achieve desirable plant communities. Such methods may include but are not limited to
education, preventive measures, good stewardship and biological, cultural, herbicide and
mechanical management.
25. Invasive —An aggressive plant capable of invading a plant community and creating a
monoculture.
26. Invasive Ornamental —A plant originally intended for horticultural or landscape situations
that has escaped its intended boundaries and is capable of invading a plant community and
creating a monoculture.
27. Landowner —Any owner of record of state, municipal or private property including an
owner of any easement, right-of-way, or estate within the county.
28. Lobe —A division or segment of a leaf or other plant part, especially a rounded one.
29. Local Noxious Weed —Any plant of local importance which has been declared an invasive
or undesirable plant by the Pitkin County Weed Advisory Board.
30. Management —Any activity that prevents a plant from establishing, reproducing, or
dispersing itself.
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31. Management Plan —A plan developed by the local Weed Advisory Board and
implemented by the Board of County Commissioners in order to control the spread of
noxious weeds.
32. Mechanical Management —Methods or management practices that physically disrupt
plant growth including tilling, mowing, burning, flooding, mulching, hand -pulling,
shoveling, hoeing and chopping.
33. Monoculture —A single homogeneous crop without diversity or dissension.
34. Native Plant —A plant species that is indigenous to a particular locale.
35. Neighboring —Any property located within a one-half mile radius of the boundary of a
subject property.
36. Noxious Weed —An alien plant or parts of an alien plant that has been designated as being
invasive and undesirable and has been declared a noxious weed by the County Weed
Advisory Board and meets one or more of the following criteria:
a) aggressively invades or is physically destructive to economic crops or native plant
communities;
b) is detrimental directly or indirectly to the environmentally sound management of
natural or agricultural ecosystems;
c) is poisonous to livestock;
d) is a carrier of detrimental insects, diseases or parasites.
37. Noxious Weed Management —The planning and implementation of an integrated program
to manage undesirable or problematic plant species.
38. Ornamental —A decorative, aggressive, non-native plant often sold through nurseries or
spread through seed collection; a threat to native plant species because it has no natural
predators and thus competes against the plants of the natural ecosystem.
39. Perennial —A plant that grows for three years or more. Usually flowering and producing
fruit each year. The above ground part of the plant may die, but new growth comes from
the roots or the crown each spring.
40. Petiole —A slender stem that supports the blade of a foliage leaf.
41. Pitkin County Weed Advisory Board —A group of individuals appointed by the Board of
County Commissioners of Pitkin County to advise on matters of management of noxious
weeds.
42. Rhizome —An elongated subterranean plant stem that produces shoots above and roots
below, and is distinguished from a true root in possessing buds, nodes and scalelike leaves.
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43. Rosette —A cluster of closely crowded leaves in a compact circle, usually at ground level.
44. State Noxious Weed —Any weed identified by the commissioner of the State of Colorado
Department of Agriculture after surveying the Local Weed Advisory Boards and
prioritizing the top ten problematic plants. Said survey is to be conducted every three
years.
45. Subject Lands —All public and private lands within unincorporated Pitkin County with the
exception of:
a) any municipal property owned or leased to an incorporated municipality;
b) any land managed or administered by a federal agency.
46. Surfactant —A compound that improves the emulsifying, dispersing, spreading, wetting,
or other surface modifying properties of liquids.
47. Weed Inspector —The agent or employee appointed to conduct the duties and functions as
defined under this plan.
48. Weed Office —The office of the Weed Inspector out of which all noxious weed
administration and enforcement activities are conducted.
49. Wildflower —The flower of a wild or uncultivated plant or the plant bearing it.
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