Kochia: A Growing Concern in the MD of Spirit River
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While the Province of Alberta has not yet regulated the plant, the Municipal District of Spirit River #133 Council has created a bylaw elevating Kochia to noxious weed status within its borders.
We join several other municipalities taking similar action recently as Kochia spreads north. This weed is a significant concern for livestock farmers; it contains saponins, alkaloids, oxalates and nitrates, which can be toxic if consumed in large quantities.
Origins and Characteristics
Kochia (Bassia scoparia) is a summer annual broadleaf weed native to Eurasia, introduced to North America by European immigrants in the mid-1800s as an ornamental plant.
Widespread across arid and semi-arid regions, it is already considered noxious in Manitoba and Saskatchewan. Also called burning bush, Mexican fireweed or tumbleweed, it is recognized for its red fall foliage and wind-dispersed seeds.
The plant is highly adaptable, growing from 15 cm to over two metres tall. Its deep roots extend up to five metres, with a horizontal spread of 2.4 metres, allowing it to thrive in dry or saline soils. Kochia germinates early in the spring and tolerates frost, drought and salinity.
This makes it a fierce competitor: extreme infestations of 195 plants/m2 have reduced wheat yields by up to 73 percent.
Reproduction and Dispersal
Kochia reproduces exclusively by seed, yielding 15,000 to 25,000 seeds per plant. The seeds are small, flattened and enclosed in a paper-like hull. As the plant matures, an abscission layer forms near the soil. The entire plant detaches and rolls across the landscape as a “tumbleweed,” scattering seeds over long distances. This dispersal method, combined with rapid early growth, makes it very difficult to manage.
Herbicide Resistance and Management
Herbicide resistance is a severe issue. Resistance has been documented across multiple herbicide groups, including Groups 2, 4, 9 and 14.
By 2019, 87 percent of tested Kochia plants in Saskatchewan were glyphosate-resistant. Many exhibit stacked resistance, severely limiting chemical control options.
Management requires a proactive, integrated approach:
Early Control: Treat before the weed exceeds 10–15 cm.
Chemical Application: Use pre-seed spraying and early in-crop spraying at the button
stage, using high water volumes to penetrate dense leaf hairs.
Cultural Practices: Utilize diverse crop rotations, zero tillage and mowing before seed set.
Because Kochia seeds rarely persist in the soil beyond a year, preventing a single season’s seed set can drastically reduce future infestations.
Alternative Uses
Despite its risks, Kochia is sometimes used as a drought-resistant forage crop due to its high protein content. However, it must not exceed 50 percent of a livestock animal’s diet to prevent toxicity.
For questions or concerns, please contact the MD’s Agricultural Fieldman, Simon Amting, at
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