General: Common Burdock is a biennial herb that grows 0.5-1.5 m tall and produces burs with hooked bristles that can cling onto clothing, equipment, and animals. These burs were actually the inspiration for Velcro!
Flowers: Flowers mature into a brown, circular-shaped bur. Before this stage, the flowers are purple on green circular-shaped burs that are approximately 2.5 cm in diameter, with hooked green bristles.
Stem: The stem is upright, grooved, and has a reddish tinge towards the base of the plant.
Leaves: The green leaves are large, heart-shaped and hairy underneath, with wavy edges and a slight upwards curl. The leaves appear to be rhubarb-like in appearance and form a rosette in the first year.
Roots: Common Burdock has a thick and fleshy taproot.
Native: Cocklebur (Xanthium strumarium): Has smaller, spiny leaves.
Non-native:Great Burdock (Arctium lappa): Has larger flowers than Common Burdock, with solid lower leaf stalks.
Habitat and Origin
Common Burdock was unintentionally introduced from Europe to North America. The first sighting of this species in North America was reported in 1638. Common Burdock thrives in moist, fertile, and nitrogen-rich soils of disturbed areas such as roads, ditches, and riparian areas.
Propagation & Vectors of Spread
Common Burdock propagates by seed and can produce 6,000-16,000 seeds per plant in the form of burs, during its typical life span of four years. Seeds are shed throughout the fall, winter, and following spring, while the majority of seeds germinate in early spring. Common Burdock spreads by its clinging and prickly burs, which attach themselves to animals, clothing, and equipment. The burs can remain on animals for several weeks and be carried more than 10 kilometers.
Ecological and Economic Impacts
- Crowds out forage grasses in pastures and other native vegetation.
- Harms native fauna species with its burs, as there have been occasional incidences where birds and bats have become entangled in the burs and perished.
- Hosts powdery mildew and root rot, which can spread to farmer’s crops and reduce crop yield.
- Taints dairy products when grazed by livestock.
- Burs can become tangled in horses’ manes and sheep’s wool, damaging their quality and reducing their value.
What Can I Do?
Common Burdock is found throughout the Sea to Sky Region, so STRATEGIC CONTROL is key:
Learn to identify Common Burdock: use the images presented in this profile page to learn how to identify Common Burdock.
What to do if you spot it: You can report any Common Burdock sighting by clicking here.
- Regularly monitor properties for weed infestations.
- Ensure soil and gravel are uncontaminated before transport.
- Maintain and establish healthy native plant communities to help resist invasion.
- Remove flowering heads and burs from personal gear, clothing, pets, vehicles, and equipment.
- Ensure that all flowering heads and buds are bagged and disposed of in the household/general waste stream at the landfill.
- Unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
- Compost any flowering heads or burs. Instead, dispose of Common Burdock in the general/household waste stream at the landfill as the seeds will be able to persist the composting process.
- Move soil, gravel, or fill that has been contaminated with Common Burdock.
Mechanical control is an effective treatment for the removal of Common Burdock. Ensure that you sever the taproot below the root collar (where the stem becomes a root) with a flat-nosed spade. Learn more about it here. Mowing or tilling is also effective, but this must be done before any plants seed.
Many foliar herbicides do work on Common Burdock, but mechanical removal is quite effective, so they are often not recommended. It can be controlled with 2,4-D, picloram, dicamba, or glyphosate. Herbicides are most effective when applied to first-year rosettes. All herbicide applications should be monitored over successive years as follow-up treatments may be required, and to evaluate the efficacy of the chemical control method.
We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.
- Colorado State Parks, https://cpw.state.co.us/Documents/ResourceStewardship/CommonBurdock.pdf
- Guide to Weeds in BC, https://bcinvasives.ca/documents/Field_Guide_to_Noxious_Weeds_Final_WEB_09-25-2014.pdf
- Invasive Species Council of Alberta, https://abinvasives.ca/wp-content/uploads/2017/11/FS-CommonBurdock.pdf
- Invasive Species Council of BC, https://bcinvasives.ca/invasive-species/identify/invasive-plants/burdock/
- Invasive Species Council of Manitoba, https://invasivespeciesmanitoba.com/site/index.php?page=burdock