Kochia

Identification & Biology
Alias' : Summer cypress, burning bush, tumbleweed
Latin Name : Kochia scoparia
Category : Terrestrial Plants
Description :
  • Annual with taproot
  • Reaches heights of 0.3 – 1.5 m tall
  • Mature plants have numerous branches, often with pyramidal or rounded tops
  • Leaves are 2-6 cm long, alternate and lance-shaped
  • Flowers are inconspicuous, stalkless in the axils of upper leaves

 

Seedlings emerge early in the spring. Flowering and seed production occurs from July through to October. It often grows vigorously for 1-2 years in abandoned fields until nitrogen is depleted. Kochia is often referred to as a “tumbleweed” because the stem breaks off at the base of the plant in the fall allowing it to roll across fields like a large ball, which is an important way of spreading its seeds. Kochia has been used as a livestock feed during feed shortages resulting from drought. As a forage crop, kochi is noteworthy because it has good drought tolerance, salinity tolerance, good leafiness, high yields, and has high protein and carbohydrate content.

Habitat

In British Columbia, kochia is locally common in dry areas of the interior in roadsides, ditches and disturbed habitats. It is generally found in open, unshaded areas on disturbed sites but can move into grasslands, riparian areas and sagebrush plant communities.

Impact & Risks
  • Kochia is palatable to livestock but sometimes contains high nitrate levels and sulphate toxicity.
  • It colonizes rapidly and may suppress other vegetation. It is an early successional plant on disturbed sites and can dominate vegetation for the first two years following disturbance.
Prevention & Mitigation

The most effective way to ensure that your lands do not become infested with kochia is by prevention. Here are some recommendations to prevent kochia from invading your property:

  • Maintain your crops and natural lands in a healthy, vigorous condition to ensure a competitive plant community; competitive perennial grasses and forms utilize water and nutrients that would otherwise be readily available to kochia.
  • Regularly patrol your property for kochia plants and immediately control or remove infestations before seed set. Do not leave plants to compost as they may still produce viable seed.
  • Cooperate with adjacent landowners and encourage them to prevent kochia spread.
  • Immediately re-vegetate disturbed, bare soils with a suitable seed mixture that provides dense, early colonization to prevent weed invasion.
  • Do not move contaminated soils to a new area.
Treatment & Disposal
  • Because the majority of kochia seeds live for only one year, preventing seed production for a single year will help reduce kochia problems.
  • Delayed seeding and pre-seeding tillage or pre-seeding herbicides will help reduce in-crop weed densities. Crop rotations that use a combination of early and late sown crops and alternating seeding dates on individual fields will help keep kochia populations in check.
  • Small infestations can be hand pulled.
  • Grazing or mowing alone will not stop seed production.
  • Focus on eliminating seed production and depleting the seed bank. Combine herbicide or mechanical removal of rosettes with removal of seed heads from any plants that have bolted.
  • Before applying herbicides, read the label for full use and precautionary instructions.
  • For further information on the selection and application of chemicals to protect your crop, contact AgriService BC at 1-888-221-7141 or email AgriServiceBC@gov.bc.ca
Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.