Noxious Weeds

Overview

The most common noxious weeds found in Butler County are Field Bindweed, Sericea Lespedeza, Musk Thistle, and Johnson Grass. A brief description of each and links to more in depth descriptions are given below.

Other noxious weeds that have been found in Butler County in small infestations are Canada Thistle, Quackgrass, and Hoary Cress. A description of these weeds can be found on the Kansas Department of Agriculture website by following the links above. In addition, a photo gallery of of these and other noxious weeds can be found at the Kansas Department of Agriculture Plant Protection Photo Gallery.

Field Bindweed


Field bindweed is a perennial that reproduces by seeds and rhizomes. Vines many feet long trail over the soil and vegetation and often form dense mats. Leaves alternate along the stem and are attached to it by a short leaf stalk or petiole. Leaf size and shape may vary considerably; typically leaves are up to two inches long and ovate (egg-shaped) with a pair of basal lobes pointing down and/or outward.
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Flowers are funnel-shaped, one-inch in diameter, white to pinkish, and borne singly on long flowerstalk. Two small bracts (appendages) on the flowerstalk, 0.5 to 2 inches below the flower, distinguish field bindweed from hedge bindweed.

Review the Field Bindweed Control Plan or visit the Kansas Department of Agriculture for more information on Field Bindweed.

Sericea Lepedeza


Sericea lespedeza is a perennial with erect stems up to 5 feet tall and small hairs laying flat along the ridges on the stem. The leaves, with 3 leaflets, are less than 1 inch to 1.5 inches long and 0.25 to 0.5 inch wide with the larger leaflets on the lower portion of the stem. The leaves are flattened on the outer end with small flat hairs on the lower surface. Flowering occurs from mid or late July to October and may be tinged with purple but always dry to yellow.
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The tannin content of sericea lespedeza increases during the growing season making it unpalatable to livestock during mid to late season grazing.

Review the Sericea Lespedeza Control Plan or visit the Kansas Department of Agriculture for more information on Sericea Lepedeza.

Musk Thistle

Musk thistle normally requires two years to complete its life cycle (i.e. biennial or winter annual). Occasionally, the plant completes its life cycle in one growing season (i.e. summer annual). the typical biennial musk thistle exhibits itself the first year in the from of a rosette, a cluster of tightly packed leaves laying flat on the ground.

Rosettes vary in diameter from a few inches to 3 feet. Musk thistle overwinters as a rosette. During the rosette stage (either fall or spring) musk thistle is most susceptible to chemical control. In its second year of growth, the musk thistle plant will leave the rosette stage as its stem elongates (bolts) toward the mature, flowering plant. Chemical control is less effective during the bolted stage and chemical susceptibility continues to decline as the plant reaches maturity.
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The leaves of musk thistle are deeply lobed (segmented), hairless, and are dark green with a light green mid-rib. A silver-gray leaf margin is characteristic of each spine-tipped lobe. The leaf base extends down the stem to give the plant a winged appearance.

Musk thistle is the first of the Kansas thistles to bloom in the spring. Flowering begins in mid-May and continues through early July. Each head consists of many tightly packed rose to purple colored flowers encased in a series of spine-tipped, green bracts. The terminal (uppermost) head is 1.5 to 3 inches in diameter, solitary, and generally bent over or nodding. The mature plant is generally branched, with lower branch producing one or more heads. Flowering begins with the terminal head and progresses downward. Musk thistle heads are distinguished by their "powder puff" shape.

Review the Musk Thistle Control Plan or visit the Kansas Department of Agriculture for more information on Musk Thistle.

Johnsongrass


Upright perennial grass, reproducing by rhizomes and seeds. Well adapted to compete with crop plants. Stems up to 6 to 8 feet high or more, from a freely branching fibrous root system, which produces extensive rhizomes within six weeks of germination. Leaves alternate, simple, relatively wide and long. Spikelets 1-flowered, in groups of 3, in large open panicles. Fruit a caryopsis or grain, finely striate, reddish-brown with two knobbed rachillae extending upward from the base of the seed. Flowers from May until frost and seeds to frost.

Review Johnsongrass Control Plan or visit the Kansas Department of Agriculture for more information on Johnson Grass.
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Non-Noxious Thistles

Wavy leaf thistle is probably the most common thistle since it is native to Kansas. It has a pale pink flower with a base shaped like an urn which makes the flower resemble the shaving brush and is in bloom from May to July. The leaves are covered by fine white hairs giving them a dusty appearance. Although this plant spreads by both roots and seeds, it is seldom a problem.

Bull Thistle is also common in Butler County. It is a hairy, dark green biennial plant that blooms from August to September. The shaving brush like blooms are usually purple. This plant spreads rapidly in pastures if not controlled.

Tall or roadside thistle is the other commonly occurring thistle found in this area. It is easily distinguished by a leaf that is dark green on top and silver on the bottom side. These thistles are common along roadsides as the name implies. They bloom in August and September, but seldom cause production losses.
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Visit the Kansas Department of Agriculture or Kansas State Research and Extension Site for more information.
The 2020 Chemical Weed Control Book is now available online.