Himalayan Balsam

Stem: The hollow, purple/reddish stem grow between 1-3 m tall.

Flowers: Himalayan balsam’s pink flowers are a key ID feature in the late growing season. The flowers have a hooded shape and look similar to a policeman’s helmet.

Leaves: This plant has long, toothed leaves 5-23 cm long.

Seeds: Himalayan balsam seed capsules will hold up to 16 seeds. This plant is a “touch-me-not” plant, which means that when its seed capsules mature and dry, they explode when touched. Seeds can spread up to 5 m from the parent plant.

Himalayan balsam is widely distributed across Canada and can be found all of provinces except Saskatchewan. It has naturalized in the United States.

Himalayan balsam produces dense stands, creating monocultures and reducing biodiversity by limiting nutrient and habitat availability and shading out native plants. 

Himalayan balsam’s prolific nectar production draws pollinators away from other plants and is a main draw for gardeners wanting to attract more pollinating species. However, growing this plant should be avoided, as it spreads rapidly and will quickly overtake native species and reduce biodiversity.

One Himalayan balsam plant can produce over 800 seeds, allowing them to spread quickly – both naturally through wind and animal dispersal, and through human interference once the seed pods dry and explode when touched.

This species can aggressively replace native perennial plants along riverbanks, over time leading to soil erosion.

Mechanical control, by repeated cutting or mowing, is effective for large stands, but plants can regrow if the lower parts are left intact. Cutting the plant below the lowest node can help stop regeneration. Access to the sides of riverbanks can be difficult and inaccessible stands can quickly recolonise accessible cleared areas, so vigilance is needed if an area is to be effectively cleared.

Smaller infestations can be easily controlled by hand-pulling, as the root of Himalayan balsam is very shallow. However, management should only take place if there are no visible seeds, as disturbing the seeds can lead to further infestation in the disturbed soil. If management must take place when seeds are present (typically in late May), place a bag over the top of the plant to avoid further dispersal. As the seeds are not very robust and only last about 18 months, management can be completed in two years as long as proper disposal has occurred and all plants have been removed. 

Once plants are removed, they should be placed in a black garbage bag and placed on an impermeable surface for up to 1 week. This will kill off any viable materials before disposal.