- Pest Type: Weed
- Crops Affected: Cereals, Wheat, Cotton, Potatoes, Soybeans, Corn
- Scientific Name: Kochia scoparia
- Pest Order: Chenopodiaceae
An erect (0.3-1.5 m tall) profusely bushy branched annual with fine textured foliage. Seedlings are often, but not always, pink underneath. The seedling forms as a rosette and have long hairs on the surface. As plants grow, they are blue-green to gray-green in color but take on a reddish or purplish coloration later in the season. The flowers of kochia lack petals and instead, have 5 winged sepals that are green in color.
Reproduction is by seed, and seedlings emerge in the spring. The seed are about 1.8 mm long, irregularly shaped, brown with yellow markings, and grooved on each side.
Cotyledons are narrow (about 4.5 mm long by 1.25 mm wide), elliptic to oblong, sessile, thick, dull green above, often magenta on the underside, narrow and covered with soft fine hairs. Young leaves are grayish with dense soft hairs, linear to narrowly elliptic or oblanceolate and pointed at the apex.
Blades are sometimes magenta-tinged beneath, and the leaves lack defined petioles. Young plants initially develop into a basal rosette. Elongated stems are hairy and may be reddish.
Stems are erect, much-branched, round, often red-tinged, usually with soft hairs above. Leaves are simple, sessile, alternate, linear to lanceolate (2.5-5 cm long), and hairy to almost smooth, with entire, hairy margins.
Taproot with a branched fibrous root system.
Small, green, inconspicuous flowers are produced from July to September in small spikes (5-10 mm long) in the upper leaf axils and in terminal panicles. Spikes are subtended by leafy hairy bracts (3-10 mm long). Fruit are small bladder-like utricles.
Dried plant material persists into the winter. Bracts subtending the flowers are generally evident.
Kochia is a drought-tolerant weed of dryland grain crops, rangeland, pastures, and waste areas.
Introduced as an ornamental for its bright red autumn color, kochia escaped to become naturalized throughout most of the northern half of the United States and western and southwestern rangelands. Significance of this weed is increasing eastward as well. It is one of the most abundant weeds in the Canadian prairie provinces.
The inflorescence is similar to that of the closely related common lambsquarters. It can also resemble mugwort. However, the leaves of kochia are narrow, whereas those of both common lambsquarters and mugwort are toothed or lobed and considerably wider than kochia leaves.