Noxious Weeds

Noxious Weeds Within Mitchell County, KS
Photos & Descriptions ... Mitchell County Weed Department

Stan Deneke | Cyndee McCullough

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.
Flowers are funnel-shaped, one-inch in diameter, white to pinkish, and borne singly on the long flower stalk.
Two small bracts (appendages) on the flower stalk, 1/2 to 2 inches below the flower, distinguish field bindweed from hedge bindweed.

Information referenced from “Field Bindweed: A Noxious Weed in Kansas,” published by the Kansas State Board of Agriculture Plant Health Division, June 1986.

Hoary Cress

Hoary cress is a perennial Forb that originated in Eurasia. It flowers from April through June, and reproduces through rhizomes and seeds.
Found in pastures, small grain fields, roadsides, ravines, meadows, and waste places, livestock will graze hoary cress, but only when better forage is unavailable. Its seed are eaten by ground-foraging birds. The foliage of hoary cress contains a substance causing irritation to mucous membranes of animals. It is only a problem when forage is in short supply.
The plant can grow up to 2 feet tall and have many white flowers with four petals, and each flower is clustered into groups.
Hoary cress is an aggressive weed that often forms large, dense stands which are difficult to eradicate or control.

Johnsongrass

Johnsongrass is an upright perennial grass, reproducing by rhizomes and seeds.
It is well adapted to compete with crop plants.
Stems reach up to 6 to 8 feet high or more, from a freely branching fiberous root system, which produces extensive rhizomes within six weeks of germination.
The leaves alternate, simple, relatively wide and long.
Spikelets are 1-flowered, in groups of 3, in large open panicles.
The fruit is 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.

Information referenced from “Johnson Grass,” published by the Kansas State Board of Agriculture Plant Health Division.

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 three 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.
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 1/2 - 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.

Information referenced from “Musk Thistle: A Noxious Weed in Kansas,” published by the Kansas State Board of Agriculture Plant Health Division.

Bull Thistle

The Bull Thistle is also becoming more common in Mitchell County and is a county optioned noxious weed.
Branching, erect biennial, 2 to 6 feet tall.
Long, sharp spines on the leaves at the midrib and the tips of the lobes.
Leaves are deeply lobed and hairy - there are coarse hairs on leaf tops, making leaf feel rough to the touch, and woolly hairs on the underside.
Leaf bases extend down onto stems and form spiny wings along the stems.
The shaving-brush-like blooms are usually a purplish pink-magenta flower head atop each stem.
Flower heads are “gumdrop” shaped and spines extend all around the base of the flower heads.
This plant spreads rapidly in pastures if not controlled.
This hairy, dark green perennial plant will bloom from August to September.

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