Canadian Horseweed (Canadensis)

The Canadian Horseweed (Canadensis) is generally described as a biennial forb/herb. This is native to the U.S. (United States) has its most active growth period in the spring and summer and fall . The Canadian Horseweed (Canadensis) has green foliage and inconspicuous white flowers, with an abuncance of conspicuous brown fruits or seeds. Leaves are not retained year to year. The Canadian Horseweed (Canadensis) has a short life span relative to most other plant species and a rapid growth rate. At maturity, the typical Canadian Horseweed (Canadensis) will reach up to 5 feet high, with a maximum height at 20 years of 0 inches.

The Canadian Horseweed (Canadensis) is not commonly available from nurseries, garden stores and other plant dealers and distributors. It can be propagated by seed. It has a rapid ability to spread through seed production and the seedlings have high vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below 52°F. has low tolerance to drought and restricted water conditions.

Plant Basics
Growth Rate Rapid
General Type Forb/herb
Growth Period Spring, Summer, Fall
Growth Duration Annual, Biennial
Lifespan Short
Plant Nativity Native to U.S.
Commercial Availability No Known Source
Physical Characteristics
Bloom Period Indeterminate
Displays Fall Colors No
Shape/Growth Form Single Crown
Drought Tolerance Low
Shade Tolerance Intolerant
Height When Mature 5
Vegetative Spread None
Flower Color White
Flower Conspicuousness Yes
Fruit/Seed Abundance High
Seed Spread Rate Rapid
Gardening Characteristics
Propagations (Ways to Grow) Seed
Moisture Requirements Medium
Cold Stratification Required No
Minimum Temperature 52
Soil Depth for Roots 6
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Regrowth Rate Slow
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 4.8–7.2 pH
Precipitation Range 14–14 inches/yr
Planting Density 0–0 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 6
Minimum Frost-Free Days 60 day(s)
Salinity Tolerance None
CaCO3 Tolerance Low
Sustainability & Use
Leaf Retention No
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA