Biennial & Perennial Weeds
THISTLE: BULL, MUSK, PLUMELESS Cirsium vulgare, Carduus nutans and Carduus acanthoides Life Cycle: Biennial Plant Description: Bull Thistle: Erect, 2 to 5 feet tall with many spreading branches, spiny wings from leaves. Rosette forms first year; flowering stem elongates second year. Leaves have short prickles on the
surface and are cottony below. Flowers are dark purple and somewhat clustered. Musk Thistle: Erect, freely branching, up to 7 feet tall. Leaves are dark green with light midrib, hairless on both sides, with long, sharp spines. Flowers are deep rose to purple, up to 3 inches in diameter. Plumeless Thistle: Branching plant with spiny wings that extend up to flowers. Stems grow 1 to 4 feet tall. Rarely flowers the first year. Flowers are purple to pink, 1 to 2 inches in diameter, solitary or in clusters of two to five. Bracts are sparsely to densely hairy.
Treatment: Apply 12 to 16 fluid ounces of DuraCor ® herbicide per acre or 1.2 to 1.5 pints of GrazonNext ® HL herbicide per acre during the rosette stage early in the season. Fall to early winter applications can be made to rosettes prior to the first hard frost.
86
Made with FlippingBook Digital Proposal Creator