Mt. Crested Butte Noxious Weed Guide

Transcription

1 Mt. Crested Butte Noxious Weed Guide PHOTO PLANT NAME DESCRIPTION COMMENTS LIST A WEEDS EFFECTIVE CONTROL METHODS PREVENTION Purple Loosestrife (Lythrum salicaria L.) erect, square stem smooth to hairy, multi-branched. 1 ½ to 8 feet tall. lance-shaped leaves. magenta grows in moist wetland sites. highly aggressive invader species. Threat to waterfowl habitat and water flow in irrigation ditches hand-pulling, digging and reseeding of invaded areas. Chemicals should not be used due to proximity to water LIST B WEEDS Absinth Wormwood (Artemisa absinthium) 16 to 48 inches tall. light gray oblong leaves ½ diam. reddish stems grows near streams, lakes or irrigation ditches surface-applied herbicides are effective with re-treatments in late June to mid-august. established perennial grass resists infestation. cutting or mowing reduces seed production Black henbane (Hyoscyamus niger L.) 1 to 3 feet tall. coarselytoothed leaves. brownishyellow with purple center and purple veins. plant has a foul odor. grows in pastures, fence rows, roadsides, and waste areas. can cause livestock poisoning. poisonous to humans surface-applied herbicides are effective when applied to younger plants. cutting reduces seed production. established native vegetation reduces infestation maintain healthy established native groundcover. learn to identify plants. know the origin of fill dirt. use only certified weed- free hay/straw and seed

2 Dalmatian Toadflax (Linara genistifoli assp) 2 to 4 feet tall. creeping plant with waxy, heartshaped leaves that clasp the stem. are snapdragon-shaped and bright yellow with orange centers well-adapted to arid sites herbicides such as Tordon or Telar if applied at proper time. cutting reduces seed production. established native vegetation reduces infestation hay/straw and seed Dame s Rocket (Hesperis matronalis) ornamental also known as Dame s Violet. ½ to 4 feet tall. range from white to purple often sold in nurseries. once planted in garden it escapes into riparian and wetland habitats. hand-pulling through roots. deadheading after bloom prevents new plants choose alternate plants for landscaping. use control methods to prevent escape. Diffuse 1 ½ to 2 feet tall multibranched main stem with white or pink member of the aster family several effective herbicides including Curtail, Milestone, Tordon or Transline. frequent tilling, pulling and cutting helps if done prior to seed production Oxeye Daisy (Chrysantheum leucanthemum) erect plant with white ray and yellow disk from June to August aggressive invader. often planted as an ornamental Escort and Telar herbicides are effective. Also commercial nitrogen. hand-pulling or digging to eliminate rhizomes. choose alternate plants for landscaping. use control methods to prevent escape.

3 Scotch Thistle (Onopordum acanthium) Can reach height of 8 feet with leaves up to 2 feet wide and 1 foot long. reddish-purple to violet every other year found primarily along roadsides and railroad beds. presents obstacle to livestock several herbicides are effective. repeated season-long mowing and digging. repeat frequently as seeds will be present 2-4 years Yellow Toadflax (Linaria vulgaris Mill) commonly called butter and eggs. bright yellow with deep orange centers which resemble the snapdragon flower. grows in mountain meadows and rangelands repeated applications of herbicides such as Tordon have proven effective when applied right after 1 st frost. long-term regular digging and pulling.. reseed any open ground with native, perennial grasses to prevent invasion Plumeless Thistle (Carduus acanthoides) height up to 5 feet. ½ to 1 inch diameter reddish-purple. leaves lack prominent white margin of musk thistle leaves. prolific seed producer. found in pastures, river valleys, and along roadsides. herbicides applied to vegetation. regular digging or cutting to prevent seeds. Leafy Spurge (Euphorbia esula L.) propagates by seed and extensive creeping roots (up to 30 feet deep). pale-green shoots with yellowgreen highly aggressive. once established will eliminate native grasses. very difficult to remove. some herbicides are effective but must be applied by a licensed operator. persistent digging or tilling. rangelands. Musk Thistle 2-6 feet tall branched

4 Spotted (Centaurea maculosa) one or more shoots up to 4 feet tall. lavender to purple found in meadows, pastures, stony hills, and on sandy flood plains. herbicides when applied early and again in fall. mowing, cutting, pulling if repeated frequently. one of the most invasive, aggressive weed plagues. It must not be allowed to spread into our fragile subalpine ecosystem rangelands and applying irrigation if necessary. Salt Cedar or Tamarisk (Tamarix ramosissima L.) deciduous or evergreen shrub or small tree 5-20 feet tall. sapling bark and stems are reddishbrown. small scale-like leaves. five-petalled pink to white enormous water consumer. forms salt crust at ground surface inhibiting native plant growth very difficult to control. several herbicides are effective but care around moist areas must be used. repeated digging has some effective results. if this plant is observed please contact Mt. Crested Butte town maintenance dept. maintaining wellestablished healthy native cover does help but does not entirely prevent invasion. Russian (Acroptilon repens) ridged stems 1 to 3 feet high. thistle-like lavender to white This aggressive weed is beginning to spread in Gunnison County and has been observed near Almont along roadways. this plant is toxic to horses. several herbicides are effective with critical timing after bud stage. after removal reseed area with native grasses. pulling and mowing are ineffective. if this plant is observed please contact Mt. Crested Butte town maintenance dept. rangelands and applying irrigation if necessary. reseed disturbed areas with native grasses

5 Scentless Chamomile (Matricaria perforatata) Aster family imported ornamental. grows ½ to 2 feet tall. bushy shape with white, yellowcentered flower has no odor. herbicides are effective when applied prior to flowering. early and successively lower mowing before first. do not buy this plant from nurseries or specify it in bed plantings. Substitute with alternate flowering plants. Field Bindweed (Convolvulus arvensis L.) member of the morning-glory family. vine-like 1 to 4 foot stems with alternate leaves. white or pink bell shaped LIST C WEEDS highly competitive weed in Colorado. roots store 2-3 years of food supply and seeds stay viable in soil for up to 40 years. Poisonous to horses. very difficult to control once established. Vanquish and Tordon with repeated applications. tilling will distribute roots and make infestation worse. strong native vegetation cover helps but will not prevent establishment or spread NOTE Biological control methods such as the introduction in plant eating insects are not included on this table. Please refer to details contained in The Mt. Crested Butte Noxious Weed Management Plan or contact The Colorado Department of Agriculture/DPI Biological Pest Control Program. LAYOUT & DESIGN BY AVERY PEAK PRODUCTION & DESIGN