Laserfiche WebLink
GREATjU <br />RIVERlRIPW <br />GREENING <br />Chemical <br />Bull thistles can be spot treated with glyphosate, clopyralid, triclopyr, or metsulfuron while they are in <br />the rosette stage. <br />Biological <br />There are biological control agents available for thistle control. However, caution is warranted as the <br />available weevils have been observed feeding on native thistles. <br />Long-term Management <br />Maintaining a vigorous, diverse plant community is a first line of defense against invasion by bull thistle. <br />When bull thistle is present, simply cutting off and removing the inflorescences can prevent additional <br />seed inputs to the system. <br />Bull Thistle <br />April <br />May <br />June <br />July <br />Aug <br />Sept <br />Oct <br />Nov <br />Dec - <br />Mar <br />Foliar Herbicide <br />Mow <br />Flowering <br />Crown Vetch (Coronilla varia) <br />Description <br />Crown vetch is a perennial legume, native to Eurasia. It reproduces both by seed and vegetatively by <br />rhizomes, forming large patches. Its sprawling growth habit allows it to rapidly cover and shade out <br />native vegetation. A single plant may fully cover 70 to 100 square feet within a four-year period. Leaves <br />are pinnately compound with 15 to 25 pairs of oblong leaflets. The two -toned pink and white flowers <br />are arranged in umbels on long stalks. Slender finger -like seedpods develop after bloom. The mechanism <br />of seed dispersal is not known, however animals likely play a role, since some populations turn up miles <br />from a nearby seed source. Crown vetch blooms from May through August, during which time it is very <br />conspicuous with its profuse pink blossoms. <br />Crown vetch has been grown extensively in the northern two-thirds of the United States as a temporary <br />ground cover, for erosion control, and as a green fertilizer crop. It prefers open, sunny areas; typically <br />occurring along roadsides, other rights -of -way, and in open fields and prairies. Where it establishes, it <br />readily displaces native plants and decreases biodiversity. <br />Mechanical <br />Crown vetch can be mowed in June when the plant is flowering. Mowing slows the growth of the plant <br />and removes thatch, making future chemical applications more efficient. Repeated mowing can be used <br />to negatively impact the plant long-term. Plants can be pulled where infestations are small and soil <br />conditions are amenable. <br />