Himalayan Balsam (Impatiens glandulifera) is an herbaceous invasive species also known as touch-me-not. This species is commonly found in riverbanks, swamps, meadows, or other moist habitats. You can identify this species by looking for a plant that is up to 6.5 feet tall and has egg-shaped saw-toothed leaves. The stems are often hairy (glabrous) and have a purple tint. The flowers can be pink, purple, blue or white and blooms in the summer. Michigan is home to orange jewelweed (Impatiens capensis) which looks similar to Himalayan balsam. Orange jewelweed has orange flowers, is shorter, and there are fewer teeth on the leaves.
Have you seen this species? Report it to us or on the MISIN website or smartphone app! Please include a photo to help with ID verification.
Environmental Effects
Himalayan balsam has explosive seeds that can disperse on their own once they are ripe. This produces large dense patches which reduces native diversity. Due to their shallow root systems, there is an increase in erosion when there are dense patches along waterways. Pollinators prefer this species over natives because of the abundant amount of nectar produced. This further increases competition with native species.
Treatment
There are several treatment options available. This includes both mechanical and chemical controls. Please note that none of the mechanical controls should be carried out after seed capsules have matured.
NON-CHEMICAL CONTROL METHODS:
Hand pulling: since this species has shallow roots, hand pulling is both easy and effective. It is best to pull the plant out by the base to avoid breaking the stem. You should expect to pull the same area at least twice in one season. If seeds are present when you remove species plan to bag and dispose the plants. Note: the best time for this method is before the plant flowers in early June.
CHEMICAL CONTROL METHODS:
Foliar spraying: if you are treating a dense patch this is a viable option. It is most effective to spray the plants early in the growing season to avoid seed development. Note: follow all pesticide label guidelines and wear proper personal protection equipment.