A member of the Goosefoot family (Chenopodiaceae) native throughout Eurasia, Kochia scoparia (KOH-kee-uh sko-PAIR-ee-uh) is believed to have first arrived in the United States in the mid to late 1800s as an ornamental plant.
Since that time, Kochia scoparia grass has served as a ground cover, erosion control, phytoremediation plant, livestock feed, and is now often considered a fast-spreading weed.
It has a number of common names, including:
- Broom cypress
- Burning bush
- Common Kochia
- Common red sage
- Mexican fireweed
- Mexican summer-cypress
- Mock cypress
- Poor man’s alfalfa
- Railroad weed
- Summer cypress
This annual bush also has the alternate scientific name of Bassia scoparia.
In autumn, the branches shift in color from green to red, lending to many of its nicknames.
Kochia scoparia Care
Size & Growth
When left alone, this plant may grow to be anywhere from 1’ to 6’ feet tall.
Larger plants tend to have frequent branching towards their base.
The lanceolate to oblanceolate leaves appear alternately along the branches and grow up to 2 ½” inches long and ¼” inch wide.
It has a taproot which extends up to 8’ feet deep and can absorb moisture from a radius equal to the taproot length.
In late autumn to early winter, the central stem breaks away from the taproot, turning the bush into a tumbleweed.
Flowering and Fragrance
Fireweed produces 2” to 4” inch long, hairy bracts with 2 to 6 small, light green flowers each.
The inflorescence generally appears in late July and lasts into November, producing utricle (single-seed) fruits starting around late August.
Light & Temperature
Kochia enjoys full sun and may be planted in every USDA hardiness zone with the possible exception of Alaskan zones.
Watering and Feeding
As fireweed can thrive in near-desert conditions (as low as 6” inches of annual rainfall), there are no watering requirements.
You will need to restore nitrogen to the soil, generally with a dose of 50 to 100 pounds per acre before planting and an additional 50 to 100 pounds late in the growing season, based upon the estimated yield.
When using to feed livestock, be aware that the plants are naturally low in phosphorus, so supplements will be necessary.
Soil & Transplanting
Like the ice plant succulent, summer cypress has the ability to grow in places where other plants fail, including very low soil quality.
It loves alkaline soils, but may not fare well in acidic soil.
More about Caring for Ice Plant here.
Grooming And Maintenance
Harvesting Kochia for hay should occur while the plant is still young and green.
This reduces the toxicity of the hay and ensures multiple crops per year.
It also serves to reduce invasive spreading by preventing the plant from reaching its tumbleweed phase.
Try to avoid too much grazing during extreme drought, as this may increase the plant’s toxicity.
How To Propagate Burning Bush?
Propagation may be performed through seed starting in April.
While germination may occur in almost any condition, it’s best to till the ground first to ensure it won’t be overtaken by grasses.
Seeds have a very short shelf life and should be planted the next spring to ensure viability.
Common Kochia Pest or Disease Problems
Mexican fireweed’s use of tumbleweeds to spread has resulted in it becoming classified as invasive garden plants or a weed in many states.
It is currently known to be banned in Connecticut and restricted in Washington State and Oregon, so it’s important to check with your state or local Department of Agriculture office before adopting this plant.
Note that it can be very difficult to eliminate this plant once it becomes invasive.
Natural grasses will eventually overtake Kochia infestations, but it’s developed a resistance to many herbicides, especially once it becomes established.
This plant has also been known to serve as a host for various fungi and insects that may harm crops or other plants while not affecting the Kochia itself.
Mexican fireweed is known to be especially harmful to alfalfa, potatoes, sugar beets, and wheat crops.
It is resistant to most insects, although grasshoppers and Virginia tiger moths are both known to snack on the plant’s leaves.
Deer and prairie voles are known to graze on the plant.
While somewhat edible for livestock in its younger stages, large quantities of adult plant matter are toxic and may result in neurological issues or photosensitization.
It is also known to accumulate large amounts of calcium oxalate.
It is both saline tolerant and highly drought resistant.
Suggested Kochia Scoparia Uses
Fireweed’s ability to grow in otherwise hostile conditions and high protein content has made it a popular livestock feed, although care must be taken to mix it with other feeds due to its toxicity in large doses.
The long taproot makes it a good temporary soil stabilizer along banks until grasses can take over.
It is also being considered as an addition to phytoremediation planting in highly toxic areas, such as nuclear and chemical spill zones due to its ability to soak up harmful substances from deep underground.
The seeds have been used for a wide range of herbal remedies, especially in Chinese medicine.
The plant attracts songbirds, although it proves of no interest to pollinators.
Leaves are edible in small quantities when properly prepared, and the stems are often used to make brooms.