Noxious Weed Management Pocket Guide

Home , Noxious weed

Noxious Weed This brochure was created to increase Weed Control Methods awareness of noxious weeds, the What are noxious weeds? Management importance of identification, the Noxious weeds are non-native plants that dis- Preventive: Prevention is the first and, per- importance of a weed management rupt native vegetation because they have no haps, the most important step in a weed con- program, and some methods of weed natural controls and are able to adapt to varied trol program. In addition, prevention is proba- Pocket Guide control based on local, state and conditions. As a result of the Colorado Noxious bly the most cost-effective method of weed national research-based information. Weed Act, these weeds have been placed on control. Methods include: maintaining healthy three separate lists (weed names are color- pastures, using weed-free crop seed, weed- coded corresponding to the list they are on): free manure and hay, and clean harvesting How do I control weeds on and tillage equipment, as well as the elimina- tion of weed infestations in areas bordering my property? List A plants: Eliminated everywhere cropland, and in irrigation ditches and canals.

1. Identify the weeds on your property. List B plants: Spread should be stopped Cultural: Methods include, and are not limited to: Establishing and managing an ade- 2. Once a weed is identified, under- List C plants: Control is recommended quate population of desirable vegetation to stand the life cycle of the weed compete with the weeds; utilizing livestock winter or summer annual (cattle, goats, sheep) when possible; mulch- biennial ing; burning; and even plastic weed barriers.

simple or creeping perennial Mechanical: Methods include, and are not 3. Understand the types of controls limited to: Hand-pull, hoe, mow and tillage. Preventative ● Biological

Cultural ● Chemical Biological: Biological weed control involves Mechanical Palisade Insectary - Home of Colorado’s the utilization of natural enemies for the con- 4. Develop a weed management plan Biological control program (CO Dept of Ag) trol of specific weed species. Biological weed control is never 100% effective, and can take planning saves money and Effective management occurs over time 5 to 10 years for success. However, this increases effectiveness and requires repeated exposure to control method can be successful especially when methods. After years of managing weeds Courtesy: Bob Hammon include long term monitoring to combined with other control methods.

address any reinfestations. on your property, infestations should be significantly reduced enabling you to limit timing is a critical part of successful Chemical: Always read the label before efforts to the occasional, scattered plant. weed control. Regardless of which using any herbicide! Weed control with herbi-

combination of control methods are cides is an effective tool for many target This brochure is not meant to be all inclusive or used, implementing those control weed species. However, there are several restrictive, but offers guidelines and recommen- aspects to consider when choosing a chemi- methods at the correct stage of dations. References for this guide are thanks cal program. These include: ID of target weed development will increase the to the following sources: weed; herbicide selection; timing of applica- chances for successful weed con- tion; desirable crops or plant species near trol in the shortest period of time, CO Dept. of Ag. - Noxious Weed Management Program http://www.colorado.gov/cs/Satellite/Agriculture-Main/CDAG/1167928159176 control areas; the number of applications per Third Edition - Sept 2013 with the least cost. year, and the number of years for treatment. CO Weed Management Association - Noxious Weed Info. Sprayer calibration methods can be obtained http://www.cwma.org/ Colorado Stale University, U.S. Department of from your local Extension office. Agriculture and Colorado Counties cooperating. It takes persistence Compiled by: (Sprayer Calibration Fundamentals) Cooperative Extension programs are available to all http://www.ext.colostate.edu/pubs/farmmgt/05003.html without discrimination. To simplify technical John Rizza to win the Small Acreage Management Specialist terminology, trade names of products will be used. No Always add a nonionic surfactant @ 0.32 oz/ endorsement of products named is intended nor war on weeds! (970) 243-5068 Ext. 128 criticism implied of products not motioned. [email protected] gal (1qt/100 gal) unless otherwise noted. http://www.ext.colostate.edu/sam/

Bull thistle Canada thistle Musk thistle Plumeless Thistle Cirsium vulgare (Savi) Tenore Cirsium arvense (L.) Scop. Carduus nulans Carduus acanthoides L

Keys to ID Keys to ID Keys to ID Keys to ID Flower heads occur in Leaves are prickly- Purple flowers form in Broad, spine-tipped clusters of 2-5, purple to hairy above and cot- clusters of 1-5 per branch. bracts located under the flower dark red in color. tony below. Floral bracts are spineless. Flowering heads are terminal, solitary, and Alternate leaves, stalk-less, usually nodding Heads cobwebby- Small heads, vanilla scent. hairy on bottom. pubescent Grows up to 6 feet tall

Flowers are composite and purple

Identification Identification Lifecycle: Perennial Lifecycle: Biennial, or sometimes winter annual Identification Identification Growth form: Perennial forb Growth form: Forb Flower: Flowerheads are purple and borne in clus- Lifecycle: Biennial Lifecycle: Biennial Flower: Heads are terminal, solitary, 1 1/2-3 in ters of 1-5 per branch. Heads are only about 3/4 in wide, and usually nodding. Deep rose, violet or Growth form: Forb Growth form: Forb/herb wide. June-Oct. purple, occasionally white. Flowers are subtended Flower: Solitary at the ends of branches or in Flower: Flowers are 1.5-2 in wide and clustered Seeds/Fruit: One-seeded fruits (achenes) are straw by broad, spine-tipped bracts. May-July. clusters of 2-5. Bracts appear as sharp spines. at the ends of branches. The flower bracts are or light brown, straight or slightly curved Seeds/Fruit: One-seeded oblong fruit (achene) Purplish-pink; heads are 1-2 inches in diameter somewhat tapered and covered with spines Leaves: Leaves are spiny, alternate, oblong or about 0.2 inches long, shiny, yellowish-brown with a Leaves: Alternate, stalk-less, hairy underneath, plume (pappus) of white hair-like bristles. (Whitson et al. 1996). lance-shaped, with the base leaves stalkless and coarsely lobed, basal leaves spiny. clasping, or extended down along the stem. Leaves: Alternate, dark green, deeply lobed, and Seeds/Fruit: Seeds are capped with a circle of Stems: Spiney, can reach 48” tall. Stems: Mature plants range from 2-4 ft tall. spiny margined. The leaves extend onto the stem plume-like white hairs. giving a winged appearance. Basal rosettes are Roots: Fleshy taproot. Roots: Two types of roots, horizontal and vertical. well developed, leaves elliptical to lanceolate, 6-14 Other: Plumeless thistle are distinguished from Leaves: Leaves are alternate. Bull are the only The horizontal roots produce numerous shoots, in, smooth to densely hairy. musk thistle by the leaf-like spines on stem and thistles in Colorado that are prickly hairy on the while vertical roots store water and nutrients in their hairy leaf underside; flowers are 1/3rd size of musk. top surface of the leaves. They are cottony-hairy many small branches. Stems: Mature plants can grow as tall as 6 ft. It can appear solitarily or with several stems from one on the undersides. Seedling: Early spring growth appears as rosettes Control base, and is highly branched above. Stems: In mature plants the leaves extend down, with spiny-tipped, wavy leaves. Mech: Sever roots below soil surface; mow in full Roots: Fleshy taproot clasping the stem and are divided into segments Other: The floral bracts are spineless. bloom and dispose of flowering heads-seeds can

(i.e. strongly decurrent). Control mature after plant is cut. Monitor and retreat as

Control necessary to prevent reoccurrences. Mech: Mowing can be effective if done every 10 to Mech: sever the root below the soil surface. Mowing Control Bio: Seedhead weevil (Larinus minutus). Mech: sever the root below the soil surface 21 days throughout the growing season. is most effective when plants are at full-bloom. Bio: Urophora stylata, a fly predator, can be Bio: Cattle, goats, and sheep will graze when plants Bio: seed head weevil and the crown weevil are used to help control this thistle. are young and succulent in the spring. effective on large infestations. HERBICIDE RATE TIMING HERBICIDE RATE TIMING HERBICIDE RATE TIMING HERBICIDE RATE TIMING Aminopyralid 5 fl. oz./acre Spring rosette to Aminopyralid 5 fl. oz./acre Spring rosette to Aminopyralid 5-7 oz./acre Apply to rosettes in Aminopyralid 5-7 ounces/acre Spring at the pre-bud (Milestone) early bolting or in (Milestone) early bolting or in (Milestone) 1 tsp/gal water spring or fall. (Milestone) growth stage and/or to 1 tsp/gal water fall to rosettes. 1 tsp/gal water fall to rosettes. 1 t./gal water fall regrowth. Dicamba (Banvel, 1 qt./ acre Apply to rosettes in Metsulfuron 1 oz. product/acre Spring from bolting Metsulfuron 1 oz. product/acre Spring from bolting Vanquish, or Clarity) spring or fall Chlorsulfuron 1-3 ounces/acre Spring during bud to (Escort XP) to bud stages. (Escort XP) to bud stages. 1oz./gal water (Telar DF) bloom stage and/or to 0.50 gr. / gal water 0.50 gr. / gal water fall regrowth. 0.50 gr. / gal water 2,4-D or 1 qt./acre Apply from bolting to Chlorsulfuron 1 oz. product/acre Spring from rosette Chlorsulfuron 1 oz. product/acre Spring from rosette Clopyralid + 3 pints/acre Apply from rosette to 2,4-D + dicamba bud stages in spring. (Telar) through early (Telar) through early 1 oz/gal water 2,4-D bud stage when all (Rangestar) 0.50 gr. / gal water flower stage. 0.50 gr. / gal water flower stage. (Redeem) 1.25 oz / gal water plants have emerged.

Scotch thistle Diffuse knapweed Russian knapweed Centaurea diffusa Lam Acroptilon repens (L.) De Candolle Spotted knapweed Onopordum acanthium L. Centaurea maculosa L. Keys to ID Keys to ID Keys to ID Distinguished by the pointed Keys to ID Flower heads cluster 2-5 Floral bracts have yellow papery tips of the floral bracts. and are purple spines with teeth like a Floral bracts have black tips, with The roots are dark brown and Leaves are alternate, comb and a distinct terminal spine comb-like spines of equal length. have scale leaves. stalk-less and hairy underneath. Flowers are white or lavender Flowers are pink to purple, but rarely white. Leaves are pinnately divided. Seedlings have finely divided leaves

Identification

Identification Identification Growth form: Perennial forb Identification Lifecycle: Biennial Lifecycle: Biennial or short-lived perennial Flower: Heads are urn-shaped, solitary, and com- Growth form: Forb posed of disk flowers. Floral bracts are broad, Lifecycle: Biennial or short-lived perennial Growth form: Forb ovoid, entire, and greenish at the base with papery, Flower: Heads are numerous, Growth form: Forb Flower: Broadly urn-shaped, 0.6-0.8 in tall, terminal finely hairy edges. The petals are pink or purple. 1-2 inches in diameter, with spine-tipped bracts. Flower: Flowering heads are solitary at the ends of solitary or in clusters of 2-3. Floral bracts are yellow- Seeds: Oval, grayish or ivory, with long white bris- Seeds/Fruit: One-seeded fruit (achene) is wrinkled, branches. The floral bracts are stiff and tipped with ish with a brownish margin, fringed on the sides, and tles (pappus) at the tip when young. brown to grayish-black, tipped with a plume terminating in a slender bristle or spine. The heads a dark comb-like fringe. The flowers are pinkish- Leaves: Alternate. Lower stem leaves are narrowly (pappus) of slender bristles. contain two types of flowers, ray flowers (white, rose- purple or rarely cream colored. oblong to lance-shaped, and deeply lobed. The Leaves: Leaves are alternate, large, irregularly purple, to lavender) around the edges surrounding Seeds: Have a tuft of persistent bristles. tubular disk flowers. June-Aug. upper leaves are oblong, toothed, and become lobed, and have sharp yellow spikes. Rosette progressively smaller. Rosette leaves are lance- Leaves: Alternate rosette leaves are up to 6 in long, leaves may be up to 2 feet long and 1 foot wide. Seeds: Seeds are light brown to black. shaped, tapering at both ends, broadest at the tip. and deeply lobed. The principal stem leaves are Upper and lower leaf surfaces are covered with a pinnately divided, have smooth margins, and be- Leaves: Basal leaves are stalked and divided into Stems: Mature plants are between 18-36 inches thick mat of cotton-like or woolly hairs, giving the narrow, hairy segments. Stem leaves are smaller, come smaller toward the top of the shoot. foliage a gray-green color. tall. The stems are erect, thin, stiff, branched, and alternate, less divided, stalkless, and become bract- when young are covered with soft, short, gray hair. Stems: Mature plants are 1-3 ft tall, single stemmed Stems: Mature plants can grow up to 12 feet tall, like near the flower clusters. Roots: Spotted knapweed has a stout taproot. and have a large, fleshy taproot. Stems are numer- Roots: Well-developed, recognizable by their black Stems: Upright, 4-24 in tall, highly branched, angled, Seedling: Rosettes of spotted and diffuse knap- ous, branched, and have broad spiny wings. color and presence of small scale leaves. with short, stiff hairs on the angles. weed are nearly indistinguishable. Leaves are nar- Roots: Thick fleshy taproot Seedling: The seed leaves are oval, with shallow Seedling: Finely divided leaves; covered by short hair toothed or smooth edges. The surface of the leaves row and 1-2 times pinnately divided Seedling: Forms rosette looks grayish-green, but is not hairy. Control Control Control Mech: sever the root below the soil surface. Mowing Control Mech: remove all roots below the soil surface. Mow- Mech: sever the root below the soil surface. Mowing is most effective before bloom. Mech: Mowing repeatedly before the plants bolt ing is most effective before bloom. is most effective when plants are at full-bloom. Bio: livestock, seedhead weevil (Larinus minutus), during the summer, then herbicide in the fall. Bio: Seed head and Root weevils (Larinus minutes Bio: none currently effective and the root weevil fly (Cyphocleonus achates) Bio: gall midge (Jaapiella ivannikovi) and Cyphocleonus achates)

HERBICIDE RATE TIMING HERBICIDE RATE TIMING HERBICIDE RATE TIMING HERBICIDE RATE TIMING Aminopyralid 5-7 oz/acre Spring at rosette to Aminopyralid 4-6 ounces/acre Bud and flowering Aminopyralid 5-7 ounces/acre Spring at rosette to Clopyralid + 1 qt. / ac Apply spring or fall in (Milestone) early bolt stage and/or (Milestone) stage and to dormant (Milestone) early bolt stage and/or 1 t./gal water Triclopyr the rosette stage. 1 t./gal water in the fall to rosettes. 1 t./gal water plants in the fall. in the fall to rosettes. (Redeem R&P) 1 oz./gal. water 2,4-D Amine 1 qt./acre Spring/fall rosettes - Picloram 1 qt./acre Apply in spring to Amino- 5-8 oz/acre Apply to spring Aminopyralid 5-7 oz./acre Apply spring or fall in (Tordon 22K) bud/early flower cyclopyralid rosettes to pre bud (temp must be before flowering stalk .25 oz./gal water (Milestone) 0.5 gr./gal water the rosette stage. below 85o) 1 oz/gal water lengthens. *Restricted Use 1 oz/gal water stage or fall rosette. (Perspective) or in fall. Metsulfuron 2 oz./acre Apply spring or fall in Clopyralid + 1.5-2 pints/acre Rosette to early bolt Chlorsulfuron 1-3 oz/acre Apply in spring from Clopyralid + 2-3 qts./acre Apply in spring and fall (Cimarron X-tra) the rosette stage. (Telar) pre-bloom to bloom 2,4-D (Curtail) to rosettes. Triclopyr stage of growth and/or 1.5 oz./gal water 1 oz./gal water (Redeem R&P) 0.75 oz/gal in the fall to rosettes. 2 gr/3 gal water and to fall rosettes.

Leafy spurge Oxeye daisy Purple loosestrife Hoary Cress (Whitetop) Euphorbia esula L. Chrysanthemum leucanthemum L. Lythrum salicaria L. Cardaria draba

Keys to ID Keys to ID Keys to ID Keys to ID Flowers are yellowish-green and have a pair Creeping perennial; Showy pinkish-purple flowers White flowers. of heart shape yellow-green bracts below Daisy-like; grows 10 inches to 2 feet tall. bloom in long vertical racemes Grows erect 10-24” in height each inconspicuous flower. White ray flower on yellow disk; 2” diameter. Smooth Lance-shaped leaves Leaf is 3/4-4” long with blunt The entire plant contains white, milky latex. Four sided stem. end and fine white hairs.

Identification Identification Lifecycle: Perennial, short-lived Identification Identification Lifecycle: Perennial Growth form: Forb Lifecycle: Perennial Lifecycle: Perennial Growth form: Forb Flower: Heads are solitary at the ends of branches. Growth form: Forb or woody sub-shrub Growth form: Forb Heads are white ray flowers & yellow disk flowers. Flower: Numerous small clusters of small yellowish- Flower: Purple/magenta with 5-7 petals arranged in Flower: Numerous white flowers with four petals, green enclosed by paired heart-shaped yellow- Seeds/Fruit: Fruits have about 10 ribs. long vertical racemes. plant has white, flat-topped appearance. May-June. green bracts. May-July. Leaves: Alternately arranged leaves become pro- Seeds/Fruit: Fruits are many-seeded capsules, Seeds/Fruit: Seed capsules are heart shaped, and Seeds: Oblong, grayish to purple, in a capsule. gressively smaller upward along the stem. seeds are small and ovoid. contain two reddish-brown seeds. The upper leaves become stalk-less and toothed. Leaves: Alternate, narrow (1/4” wide), 1-2.5” long. Leaves: Simple, entire, opposite or whorled Leaves: Alternate, blue green, and lance-shaped. Basal and lower stem leaves are 2-5”long, spoon- Stems: Erect and unbranched (except at flower), Lower leaves are stalked, while the upper leaves shaped. Stems: Mature plants are 10-24 in tall with Stems: Annual stems arise from a perennial root- thickly clustered, can reach 3 ft tall have two lobes clasping the stem. erect, smooth to sparsely hairy stems. stock. Stems are erect, 1.5-8 feet tall. Plants be- Roots: Extensive lateral root system. Stems: Mature plants reach 2 ft tall with erect stems Roots: Shallow, branched rhizomes. come taller and bushier as the rootstock matures. Seedling: Seed leaves (cotyledons) are linear to Roots: Short rhizomes and taproot. Roots: Rhizomatous; 29-32 inches deep Other: Oxeye daisy is easily confused with the or- lanceolate, with entire margins. namental Shasta daisy which has a root ball and is Other: Sometimes confused with fireweed Control Other: The entire plant contains white, milky latex. (Epilobium spp.), which have 4-petaled flowers. a more robust plant with larger flowers. Mech: Mowing several times before the plants bolt Foliage of the plant is smooth and hairless. Control stresses it and allows for better chemical efficacy Control Control Mech: Hand removal, prior to seed set, of isolated Bio: none currently available Mech: Hand pull or dig when soil is moist and infes- Mech: Mowing will reduce seed production, repeat individuals on small infestations. Remove the entire every 2 to 4 weeks during the growing season tations are small, be sure to pull up all roots. rootstalk. Flowerheads must be cut and disposed of HERBICIDE RATE TIMING Bio: Both sheep and goats can be effective grazers. Bio: Goats or sheep can be effective. There are no properly before a herbicide is applied. Flea beetles (Aphthona spp.), are effective espe- insect biological controls currently available. Bio: Not included in prescribed management plans Metsulfuron 1 oz/acre Apply at the early (Escort XP) bud growth stage; cially when combined with grazing and/or herbicides by the State for List A species. 0.5 gr./gal water i.e. “broccoli” growth stage. (Early Spring HERBICIDE RATE TIMING HERBICIDE RATE TIMING to Early Summer) HERBICIDE RATE TIMING Metsulfuron 1 oz/acre Surfactant is abso- Triclopyr 1-2 qts./acre Summer. If plants are (Garlon 3A) flowering, cut and Chlorsulfuron 1 oz/acre Apply at the early Picloram 1 qt./acre Spring, just after full- (Escort XP) lutely necessary. (Telar) bud growth stage; (Tordon 22K 1 oz/gal water bloom and/or fall. 0.5 gr./gal water Apply at flowering 1.3-2.5 oz/gal properly dispose of water flower heads before 0.5 gr./gal water (Early Spring to *Restricted Use*) growth stage. Early Summer) (Summer) applying Imazapic 12 oz/acre Fall only treatment Glyphosate* 1-2 qts./acre Summer during the Imazapic 12 fl. oz./acre Apply at late flower (Plateau) prior to hard freeze. Chlorsulfuron 1 oz/acre Surfactant is abso- (Rodeo - flowering stage. Cut (Plateau) to post-flower 0.4 oz/gal water (Telar) lutely necessary. aquatic safe) 1.3-2.5 oz/gal and properly dispose 2 tsp/gal water growth stage. 0.5 gr./gal water Apply at flowering 2,4-D Amine 2-3 qts/acre Early spring and fall. *nonselective water of flowerheads before + 1%methylated (Late Spring to Mid growth stage. Prevents seed forma- applying Rodeo. seed oil or Summer) 2-3 oz/gal water tion (Summer) crop oil concentrate

Absinth wormwood Common Burdock Chicory Jointed Goatgrass Artemisia absinthium Arctium minus Cichorium intybus Aegilops cylindrica

Keys to ID Keys to ID Keys to ID Keys to ID Basal rosette looks Small yellow flowers. Annual grass. Large heart shaped leaf. similar to dandelion. Silver-grey leaves. Spikelets appear to be Burs with hooked bristle. Stems reach 3-5 ft. tall and are sticky. Well branched, can “jointed” Biennial, rosette year 1, Flowers occur in clusters of 1-3 and are reach 3 ft in height. Looks like winter wheat when a seedling. tall flowering stem year 2. purple-blue-white. Sage like odor.

OSU Ext. Identification OSU Ext. Lifecycle: Perennial. Identification Identification Identification Growth form: Forb Lifecycle: Annual Lifecycle: Biennial. Lifecycle: Perennial Mel Harte Flower: Purple to blue to white, in clusters of 1 to 3, Growth form: grass Growth form: Forb Growth form: Forb each is about 1 inch in diameter with toothed petals. Flower: The seed head is 2-4 inches long with 5-10 Flower: Small, yellow, inconspicuous, numerous, Flower: Each head is bristles with hooked tips that Seed: Small, obovate, light brown and darker mot- spikelets (joints) per head. Early to mid-June. ⅛ in wide. July - August. form a round bur under a closely packed cluster of tled, and finely granular. many individual, tube-shaped, reddish-purple flow- Seeds/Fruit: Spikelets are 0.5 inches long with 1-3 Seeds: One seeded fruit, 1/16 in long, smooth, flat ers. Alone or grouped on short stalks attached to Leaves: Large and lobed with toothed margins, viable seeds. At maturity spikelets separate with a and light gray-brown in color. the end of main branches. have rough hairs on the upper and lower surfaces, segment of the stems still attached can be 3 inches to 10 inches in length. The lobes Leaves: Divided into deeply lobed leaflets, light Seed: 1/4”-long, brown, oblong, angular with a Leaves: Leaves are alternate, simple, with a flap-like green to olive green color, 2-5 in long. and dissections are not opposite, like dandelions. appendage (auricle) at the base, and a leaf blade short, stiff bristle at one end. Leaves that appear on the flowering stem are simi- Stems: 20 or more stems grow from woody crown. 0.2-0.25 in wide, with hairs Leaves: Alternate, large rosette leaves attached to lar in shape but smaller in size Covered with fine silky hairs. Stems: Mature plants are generally 15-30 in tall with the stem by way of hollow petioles that may be Stems: Can reach 3-5 feet in height and are sticky Roots: Taproot to 2 in diameter with shallow lateral one to many tillers. purple-tinged. Upper leaf surface is dark green, to glabrous to the touch. branches up to 6 ft long. underside is pale gray-green and wooly. Roots: Short fibrous root system Roots: Large brown taproot, milky sap if broken. Other: Strong sage-like odor. Stems: Year 1, stem is close to the soil surface. Control Year 2, the stem elongates reaches 2-6 feet tall. Control Control Mech: Tilling when seedlings. Prevent seed produc- Roots: Thick fleshy taproot, brown, shredded. Mech: Hand pull or dig. Mowing is effective, prior to Mech: Hand pull or dig, remove all parts of plant. tion and spread flowering. Carefully remove seed to limit spread. Repeated short mowing can stress plant. Control Bio: none currently available in Colorado Bio: Nothing available in Colorado. Bio: None currently available in Colorado. Mech: Hand pull, dig when flowering. Mowing or top cutting is effective. Intolerant of cultivation. HERBICIDE RATE TIMING Bio: Nothing available in Colorado. HERBICIDE RATE TIMING Aminopyralid 4-6 oz./acre Spring at actively grow- Glyphosate* 1-2.7 qts/acre Apply early growth, HERBICIDE RATE TIMING (Milestone) ing stage. *nonselective before spikelets 1 tsp./gal water 1-6 oz./gal water form. Aminopyralid 6-7 oz. / acre Apply at spring, HERBICIDE RATE TIMING (Milestone) after reaches 12”, 2,4-D Amine 2-4 qt. / acre Early growth of flower Imazapyr 4 to 6 oz/ acre Pre-emergence 1 tsp./gal water 2,4-D + dicamba 1 qt. / acre Year 1 rosette applica- before flowering. 1 oz./gal water bud stage in spring. (Plateau) (Rangestar, tion is most effective. (late summer) and 2,4-D + Clopyralid 2 qts / acre Apply at spring, 2 tsp./gal water early growth before Rifle-D) 1 oz./gal water 2,4-D + 3 pts. / acre Early growth stage to (Curtail) after reaches 12”, Dicamba 1 oz./gal water early bolting stage . spikelets form. 1.5 oz./gal water Aminopyralid 5-7 oz / acre Prior to bud formation. (Milestone) Picloram 1-2 pts / acre Spring seedling to early Dicamba 1 qt / acre Apply at spring, 1 tsp/gal water (Banvel, Clarity, after reaches 12”, (Tordon 22K) growth stages. DO NOT 0.75 oz / gal water or Vanquish) 1 oz./gal water before flowering. apply near trees/shrubs.

Houndstongue Salt Cedar (Tamarisk) Russian Olive Yellow Starthistle Cynoglossum officinale Tamarix ramosissima Ledeb. or T. parviflora DC. Elaeagnus angustifolia L Centaurea solstitalis

Keys to ID Keys to ID Keys to ID Keys to ID Tall shrub or small tree A tall shrub or small tree Winged stems Panicles of reddish-purple Flowers are white to Many yellowish olive- Yellow ray & disk flowers flowers with 5 petals and 5 soft, hairy sepals. pink in clusters called shaped fruits. Stiff spines at flower base Velcro-like seeds with 4 nutlets. racimes. Leaves are light green Plant has a unique blue-green color

Leaves-small and scaly above and silvery beneath.

Identification Identification Lifecycle: Biennial Identification invasivespecies.org Lifecycle: Winter annual Growth form: Forb Lifecycle: Perennial Growth form: Forb Flower: Flowers are reddish-purple, with five petals, Growth: deciduous, Identification Flower: Heads are yellow, located singly at the arranged in panicles in the upper leaf axils. loosely branched. Lifecycle: Perennial ends of branches, distinguished by sharp, straw- Flower: Whitish or pinkish in clumps 2-5 cm long on Seeds/Fruit: The fruit is composed of four prickly Growth: deciduous, small tree. colored thorns, which are up to 0.75 inches long. nutlets each about 1/3 inch long the current year’s branches. Petals retained on fruit. Flower: Small, light yellow clusters, bisexual. Seeds: two types: plumed and plumeless. Leaves: Alternate, 1-12 inches long, 1-3 inches Seeds: Very small capsule, tuft of hair at one end. Seeds: Olive-shaped fruits, silver at first becoming Leaves: Basal leaves are deeply lobed while the wide, rough, hairy, and lacking teeth or lobes. Basal Leaves: Scale-like, alternate, bluish-green. yellow-red when mature. Produces great quantities. upper leaves are entire and sharply pointed. leaves are elliptical and tapered at the base. Stems: Smooth, slender, flexible, break easily; may Leaves: Simple, alternate, narrow 2-3 inches long, Stems: Mature plants are 2-3 feet tall and have Stems: Produces a single flowering stem. Stem is become 15-25 ft. tall; reddish-brown bark. and are untoothed. Upper surface is light green, the rigid, branching, winged stems that are covered erect, stout, heavy, 1.5-3 ft tall, branched above. Roots: deep taproot, extensive spreading horizontal lower surface is silvery white with dense scales. with cottony hairs. Roots: Thick, black, woody taproot. roots. Produces adventitious buds. Stems: Has 1-2 inch thorns on trunk and branches. Roots: Taproot. Seedling: Forms a rosette in the first year Roots: Can produce root suckers. Shade tolerant. Control Seedling: Oblong, tongue-shaped cotyledons Control Cultural: Maintain healthy riparian vegetative cover. Control Control Mech: Chainsaw, bulldozer, mulching, and mowing Mech: Cut or pull, and remove entire root crown Cultural: Maintain healthy riparian vegetative cover. Mech: Hand pull, make certain to pull all the roots. MUST be combined with chemical treatments. when in the rosette stage. Remove the accumulated Mech: Brush mowing and removal of cut material- Remove all parts of plant including dry skeletons. Bio: The saltcedar leaf beetle (Diorhabda elongata) dense litter layer to stimulate germination of desired MUST be combined with chemical treatments. Mowing is NOT advised. feeds on foliage causing stem dieback. plants. Mow or cut flowering stems before seed Bio: Tubercularia canker girdles tree over time. Bio: Inappropriate, as eradication is the goal, none HERBICIDE RATE TIMING nutlets develop currently approved for use in Colorado. Bio: none currently available in Colorado Triclopyr - Foliar : 2-4 qt/acre Foliar : late spring to HERBICIDE RATE TIMING (Garlon 4) early fall **approved - Cut-stump : 100% Cut-stump : anytime Triclopyr - Cut-stump : 100% Cut-stump : Apply to HERBICIDE RATE TIMING HERBICIDE RATE TIMING aquatic label unless snow present. (Garlon 4) the cambial layer **approved immediately after the Picloram 1.5 pint/acre Apply during rosette Metsulfuron 2.0 oz. / acre Apply in spring - Basal bark : 1:3 Basal bark : anytime (Tordon 22K) Methyl + rosette to early herbicide:natural oil unless snow present. aquatic label cut-stump treatment. growth stage or 1 oz./gal water when actively Chlorsulfuron 0.50 gr./gal water bud growth Glyphosate - Cut-stump : 100% Anytime unless snow Imazapyr - Foliar : Broadcast spray (Cimarron X-tra) stages. (Rodeo) present. Treat the growing (Arsenal) or 4-6 pts./acre individual trees; low *nonselective cambium after cut; Picloram + 2,4-D 4 pints / acre Apply in spring (Habitat) or high volume spray. Aminopyrlid 5 fl oz/acre Apply during rosette **aquatic label fully wet the surface. (Grazon P+D) rosette stage. **aquatic label (Milestone) and bolting growth *Restricted Use 1 oz./gal water Imazapyr - Foliar : Foliar : late spring to 1 tsp./gal water stages. Imazapyr - Cut-stump : dilute: - Cut - stump : Apply (Arsenal) or 0.5-6.5 oz/gal water late summer; avoid 2,4-D + dicamba 1 qt./acre Apply to rosette (Arsenal) or 8 -12 oz/gal water to the cambial layer (Habitat) spray solution run-off. Clopyralid 0.67 pint/acre Apply during rosette (Rangestar, stage. (Habitat) immediately after the **aquatic label - Cut-stump : dilute: Cut -stump : anytime (Transline) to mid-bolt growth 1 oz./gal water **aquatic label cut-stump treatment. Rifle-D) 8 -12 oz/gal water except spring. 1 tsp./gal water stages.

Dalmatian toadflax Yellow toadflax Perennial Pepperweed Field Bindweed Linaria dalmatica Linaria vulgaris P. Miller Lepidium latifolium Convolvulus arvensis

Keys to ID Keys to ID Keys to ID Keys to ID Yellow flowers that are like Yellow flowers that are Dense clusters of Flowers are funnel-shaped, snapdragons with deep like snapdragons with white flowers. white to pink, and have two orange centers. deep orange centers. Leaves and stem - small bracts one inch below the flower base. Thick, waxy, bluish Stems that are woody covered with waxy Leaves are shaped like arrowheads. heart-shaped leaves that at the base and smooth to the top. layer.

wrap the stem.

Identification Identification Lifecycle: Perennial Lifecycle: Perennial Identification Identification Growth form: Forb Growth form: Forb Lifecycle: Perennial Lifecycle: Perennial, member of the mustard family. Flower: Bright yellow and resemble snapdragons, Flower: bell or trumpet-shaped, white to pink in Growth form: Forb Growth form: Forb singly on ends of branches, sharp thorns below. color, and are about 1 inch long, small bracts below Flower: Loose, elongate, bright yellow. Flower: White; packed in dense clusters near the Seeds: Capsules are round-ovate, and two-celled. Seeds/Fruit: Seeds can remain viable for 40 years. Seeds/Fruit: Fruits are egg-shaped capsules. Seeds Seeds are brown or black, circular, and surrounded ends of branches. May-Aug. Leaves: Alternate, arrowhead shaped. are sharply angular, and slightly winged. by a notched wing. Fruit: Nearly round, very small and sparsely hairy. Stems: Prostrate, many feet in length Leaves: Alternate, broad, clasping but crowded. Leaves: Soft, lance-shaped, and pale green. Mainly Leaves: Alternate, lance-shaped, may be toothed, Roots: Rhizomatous with deep taproot Stems: Mature plants are up to 3 ft tall. A single alternate; lower leaves appear to be opposite. bright-green to gray-green, basal leaves are larger toadflax plant contains from 1-25 vertical, floral Stems: Mature plants are 1-3 feet tall with 1-25 than the upper leaves. Control smooth erect floral stems covered with cottony hairs Stems: Mature plants are 1-3 ft tall. stems, are thick-walled and semi-woody. Mech: Cutting, mowing, or pulling has a negligible Roots: Deep taproot, long horizontal roots that can Roots: Deep-seated roots. Roots: May penetrate 3 ft into the soil. Horizontal effect unless the plants are cut below the surface in roots may grow to be several yards long, and can develop adventitious bud sprouts. Other: The leaves and stem are covered with a the early seedling stage. develop adventitious buds. Other: Closely related to Dalmatian toadflax (whos waxy layer. Bio: The bindweed gall mite, Aceria mahlerbae, and Yellow toadflax is similar, but has more linear leaves are shorter, wider, and clasp the stem.) Exotics: Do not have clasping bases, unlike Hoary pointed leaves, and is generally a smaller plant. bindweed moth, Tyta luctuosa are effective in Colo. Control cress leaves with clasping bases. Control Mech: Hand pulling, digging, or tilling is NOT Control HERBICIDE RATE TIMING Mech: Hand pulling, for many years after 1st detec- recommended for eradication. Mech: Hand pull/dig is not effective. Instead, mow tion, is recommended for eradication. Clarity + 1 qt/acre Just after full-bloom Bio: Calophasia lunula, a predatory noctuid moth, in spring before seed-set and combine with chemi- Bio: Calophasia lunula, a predatory noctuid moth, cal treatments. 2,4-D Amine and/or fall. Eteobalea intermediella, a root boring moth and Eteobalea intermediella, a root boring moth and (temp must be 1 oz/gal water DO NOT apply near Mecinus janthinus, a stem boring weevil are cur- Bio: none currently available in Colorado. below 85o) or under trees/ Mecinus janthinus, a stem boring weevil are Do NOT graze—toxicity is high. shrubs or where currently available in Colorado. rently available in Colorado. soils have rapid HERBICIDE RATE TIMING HERBICIDE RATE TIMING permeability. HERBICIDE RATE TIMING Chlorsulfuron 1 oz / acre Bolting to early flower. Tordon 22K* 1 qt/acre Just after full-bloom Picloram 2-4 pints/acre Apply at spring Picloram 1.5 qts/acre Apply at mid- (Telar) (Early Spring to Early *Restricted Use and/or fall. (Tordon 22K*) flowering or in fall (Tordon 22K*) flowering to late fall 0.5 gr./gal water Summer) 1 oz/gal water DO NOT apply near *Restricted 1 oz./gal water *Restricted 1 oz/gal or under trees/ Metsulfuron 1 oz / acre Bolting growth stage. shrubs or where Chlorsulfuron 2-3 oz/acre Apply at spring (Escort XP) 0.5 gr./gal water (Spring) soils have rapid (Telar) flowering or in fall Chlorsulfuron 1.25 oz/acre Apply at mid- (Telar) add to Tordon flowering to late fall Imazapyr 12 fl oz / acre Flower to late flower permeability. (Aug thru Sept) (Plateau) + 2 pt/ac seed oil growth stages. Roundup Ultra* 4-5 qts/acre Apply at full-bloom 2,4-D + Dicamba 2 qt. + 2 qt./acre Pre-bloom to flower 0.50 gr./gal water (Summer) *non-selective and/or in fall. (Rangestar) stage (retreatment add to Tordon 2 tsp./gal water herbicide 4-5 oz/gal 1 oz./gal water is essential) +1% sol. seed oil

Kochia Poisonous Plants Winter Annuals Backyard Weed Control Tips Kochia scoparia (L.) Roth These plants are poisonous to domestic livestock Select problem landscape plants Weeds (or undesirable vegetation) are a con- cern anytime they compete with the desired Keys to ID Cheatgrass - Downy brome Western Whorled Milkweed vegetation of your landscape or garden area. Grooved branches Bromus tectorum Weeds are opportunistic and will occupy any Asclepias subverticillata Erect stems can reach 5 ft. space that they can readily invade. Know that Keys to ID Keys to ID Small green flower lacks petals Drooping seedhead tolerating a few weeds can allow a healthy, Whorled linear leaves Densely hairy leaves functioning, attractive sustainable system. Greenish white flower Slender seed pod Greens early spring Proper management, whether it be healthy Milky latex sap Changes to purple/tan in early summer turfgrass, adequate native plantings, or adequate mulch depth, can help to severely limit the impact that invasive and weed plants have. Mustards - Sheperd’s-purse Capsella bursa-pastoris Identification The best weed control is Keys to ID Lifecycle: Summer annual prevention! Growth form: Forb Lobed basal leaf Flower: Head is a spike, formed by clusters of in- Deeply toothed leaf An integrated management approach to weed conspicuous, green, petal-less, stalk-less flowers Long, slender flower stalk prevention will allow for the best results to re- that grow in the axils of reduced leaves. Terminal flower cluster duce any weed concerns on your property. This Seeds: egg shaped, flattened, and very small. Small white 4-pedal flowers Leaves: Alternate, simple, linear to lance shaped. takes time and attention over the long term to Stems: Multi branched from base, erect, reddish tint Showy Milkweed Mustards - Tumble mustard achieve successful results. Roots: Taproot. Asclepias speciosa Sisymbrium altissimum Some Additional Resources: Seedling: Cotyledons are very narrow, essentially Keys to ID linear in outline, dull green in color, and covered Keys to ID Opposite elliptical leaves with hairs. Coarse deeply divided leaf Steve Anthony Pink/white crown like flower Other: seeds spread prolifically by tumbleweed Narrow lobed upper leaf Garfield County Vegetation Manager Erect stem can reach 5 ft. mechanism over vast distances Stem erect and branched (970) 945-1377 x 4305 Milky latex sap Control Small yellow 4-pedal [email protected] Mech: Till seedlings early in spring. Mow or slash flowers plants before flowering to reduce seed production. Tumbles in the wind Garfield County Vegetation Management http://www.garfield-county.com/vegetation-management/ Bio: None known. Control CSU Ext, Preparation of small spray quantities of pesticides Cultural: Maintain healthy stand of natives/desired http://www.ext.colostate.edu/pubs/garden/07615.pdf HERBICIDE RATE TIMING perennials, carefully manage grazing to ensure CSU Ext, Weed Management for small rural acreages Most Effective When Combined With Mechanical protection of desired plant species. http://www.ext.colostate.edu/pubs/natres/03106.pdf Mech: Cutting or mowing has a negligible effect, Dicamba As specified on Apply early in repeated hand pulling must be done to include as CSU Ext. Yard and Garden Publications (Banvel, the label growth before much of the remaining root system as possible. http://www.ext.colostate.edu/pubs/pubs.html#garden Vanquish, flowering stage Bio: Domestic livestock grazing, when timed cor- or Clarity) Control rectly can help reduce invasives over time. Products are listed as a service to Extension clientele. CSU Mech: Hand pulling, digging, to remove all parts of Extension does not guarantee nor warrant the standard of any Chemical: Glyphosate herbicides applied at the Glyphosate* 1-2 qts/acre “Burndown” apply plant when found in grazing pasture land, combine products, nor does it imply approval of the product to the exclu- *nonselective early in growth with chemical treatment option. recommended label rate to young seedlings will be sion of others which also may be available, nor does it intend 1.3-2.5 oz/gal before flowering effective when combined with other control water stage Chemical: Dicamba (Banvel, Oracle, Clarity) with discrimination or criticism of products or providers that are men- any 2,4-D Amine product. Rate: Mix one ounce of methods. tioned or not mentioned. In addition, CSU Extension and Garfield each product into one gallon of water (1 oz/gal). County assume no liability for use of any product.