Policeman's helmet or Himalayan balsam (Impatiens glandulifera) is a tall (1 to 2 m) annual plant with showy pink flowers that are very attractive to bees. It has hollow stems with long, slender leaves and dies back each fall.
Policeman’s helmet is relatively easy to control if it is pulled by the roots. The seeds last in the soil for up to 18 months, so it is possible to control an infestation with only 2 to 3 manual removals. Pulling the roots from the soil is a less appealing option when the plants are growing adjacent to streams as disturbance to the moist soil will likely cause streambank erosion and possible alteration to the stream course.
Alternatives for planting:
- hardhack (Spirea douglasii)
- red-osier dogwood (Cornus stolonifera)
- fireweed (Epilobium angustifolium)
- western columbine (Aquilegia formosa)
- tiger lily (Lilium columbianum) – all native species that provide habitat for native wildlife.
Policeman's helmet is an annual that germinates from February through March and flowers from June to October.Growing up to 10 feet tall, the upright stems are hollow with a purple or reddish tinge; leaves are oblong to egg-shaped, with serrated edges, with white, pink or purple flowers resembling an old-fashioned English policeman's helmet. A single plant can produce up to 800 seeds, which are viable for 18 months or more and can even germinate under water. Since the plant often grows along streams and ditches, seeds spread quickly downstream. When touched, the mature seedpods split and eject seeds up to 20 feet. This trait has earned the Impatiens family the name of "touch me not."