What is Policeman’s Helmet?
Policeman's helmet, also known as Himalayan balsam or jewelweed, is a state-listed B invasive species native to the Himalayan region of Asia. Policeman's helmet and its relatives are known for their showy flowers and ballistic seed dispersal method. It bears light pink to purple flowers and can grow up to 8 ft tall. The stems are vertically ribbed, reddish-green in color, and have red swollen nodes with small glands at the leaf base.
Policeman's helmet is becoming increasingly common in Lincoln County, with the most expansive infestations occurring along the Alsea River. Lincoln County is home to a native relative of the policeman's helmet named Touch-me-not balsam (Impatiens noli-tangeri) that is much smaller and has yellow to orange-colored flowers.
Why Is Policeman’s Helmet a Problem?
Policemen's helmets invade early successional forests near and along riparian corridors. It has the capacity to produce as many as 2,500 seeds per plant and launch them as far as 20 feet. In appropriate conditions, a policeman's helmet will grow in dense thickets that out-compete many native species. The dense growth and sheer number of flowers that a policeman's helmet produces limit pollinator exposure for native plants as well as forage opportunities for wildlife. Policeman's helmet infestations have the potential to drastically alter habitat structure.
Controlling Policeman's Helmet
Policemen's helmet infestations are readily controlled by repeated pulling or grazing. Any of these manual control methods should occur prior to flowering to prevent the dispersal of seeds. Because stem pieces can produce new roots from their nodes, plants that have been pulled should be bagged or left to dry on pavement or a tarp before disposal.
If control methods are implemented after seed maturation, the slightest touch will cause an explosion of seeds. If the flowers go to seed, it is best to avoid control until the following spring. Since the seeds remain viable for a relatively short period (approximately 1 to 2 years), implementing control practices over 2 to 3 Springs should drastically reduce an infestation.
If persistent control methods seem to be ineffective after several years, there is most likely an infestation upstream of your property. If you find yourself in this situation, share Policeman's helmet control information with your neighbors and contact the Lincoln Soil and Water Conservation District (LSWCD).
If you find a Policeman's helmet infestation, contact Lincoln SWCD by phone at (541) 265-2631 or email Lincoln SWCD.
An in-depth summary of policeman's helmet control methods can be found in the document: