Invasive Plants, Pacific Northwest
Common burdock grows all over the Pacific Northwest, I have seen it growing from the seashore right up to the tree line on our coastal mountains. The burs that grow on this plant are almost impossible to remove once stuck onto something, Velcro was developed using this plant’s ability to stick as a guide.
Burdock is a Eurasian, biennial herb that will grow in most soil conditions. Burdock (Common Burdock) plants are identifiable by heart shaped leaves that grow alternately on the stem, and purple, prickly flowers borne in clusters at the top. Burdock blooms between July and October. Seeds mature by September and are spread throughout the winter and spring. Various insects pollinate burdock, particularly honeybees, bumblebees and leaf cutting bees.
Burdock is an invasive plant in the Pacific Northwest. Invasive plants grow and spread quickly, forcing out native plants and causing damage to the health of our environment.
Common burdock can seriously damage native ecosystems. Although found primarily on disturbed sites, it will spread to natural areas from nearby roadsides, logged over areas and unused fields.
Growing to heights of up to 3 metres, its large leaves can shade out and prevent other plants from growing, having an adverse effect on crop quality. Burdock plants indirectly affect the development of economically important plants by hosting powdery mildew and root rot. If eaten by milk producing animals like cows and goats, and if they digest enough, their milk can be tainted.
Common burdock is considered a noxious weed under the BC Weed Control Act because of its ability to disperse easily, and sicken livestock.