WSU Extension

Hortsense

Weeds : Kochia : Kochia scoparia
(revision date: 3/14/2019)

Family: Chenopodiaceae
Cycle: Annual
Plant Type: Broadleaf

Use Integrated Pest Management (IPM) for successful weed management.

Biology
Kochia has a single stem reaching one to six feet high. The main stem is branched above, but typically unbranched at the base. Leaves are soft, hairy, and lance-shaped, reaching up two inches long and 1/8 to 1/2 inch wide. Leaves are alternate on the smooth stems. Stems can be striped light and dark green or green and red. The entire plant may become reddish in autumn. Short, dense clusters of inconspicuous greenish flowers are borne in the leaf axils. Kochia seeds are dull brown, winged, and about 1/16 inch long. Seed are dispersed when the plant dries, breaks away at the base, and tumbles in the wind. Fivehook bassia (Bassia hyssopifolia) resembles kochia, but the seeds have five hooked appendages rather than wings. SPECIAL INFORMATION: Sometimes used as a forage plant, kochia can be toxic to animals due to accumulation of nitrates and other compounds in the plants. In WASHINGTON and OREGON, it is designated as a Class 'B' noxious weed. Management of this species may be required by law in your county. In addition, it is on both the Washington and Oregon noxious weed quarantine lists, which prohibit sale, purchase, and transport of plants, seeds, and plant parts. Consult your local Noxious Weed Control Board for more information.
Habitat
Kochia is found in cultivated areas including fields and gardens, as well as on roadsides, ditch banks, and other uncultivated or disturbed sites. It survives well in dry areas, and is not usually a problem in maintained lawn and turf.

Management Options

Non-Chemical Management
  • Reduce weed establishment by maintaining a healthy planting or turf area to provide competition.
  • Cultivation (rototilling or hoeing) will effectively eliminate plants.
  • Hand-pull to eliminate weeds.
  • Mowing to prevent seed production is a very effective means of management. In lawns, mowing regularly at the proper height for the grass species may help minimize weed growth and invasion.
  • Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label directions. Glyphosate products should be applied as spot treatments only! NOTE: Some ingredients listed here are only available in combination. Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas
  • glyphosate
  • dichlobenil
  • products containing diquat
Turf areas
  • 2,4-D + MCPP + dicamba
Bare ground areas
  • glyphosate
  • products containing diquat
Images
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Caption: Kochia showing fall color
Photo by: J.A. Kropf
Caption: Kochia flowers
Photo by: J.A. Kropf
Caption: Kochia along roadside
Photo by: J.A. Kropf
Caption: Kochia
Photo by: D.G. Swan
Caption: Kochia seedling
Photo by: J.A. Kropf