Impatiens glandulifera is an annual flowering plant that is native to the Himalayas, but has spread worldwide since its introduction to Europe in 1839. The plant is sometimes also referred to as policeman’s helmet, bobby tops, and gnomes’ hats because the flowers on the plant are hat-shaped. It is considered an invasive plant, which technically means it is a weed, and a person should take great care when planting impatiens glandulifera in his or her garden.
The plant can grow up to ten feet (3.05 m) tall and has a long, hollow stem that can be light purple or reddish in color. Its leaves can grow to around six inches (15.24 cm) long and have saw-like edges. During warm weather months, the flowers bloom and range in color from white to a variety of pinks and purples.
Each plant can store up to 800 seeds in its seed pods. During germination, the seed pods explode and can shoot the seeds out as far out as 20 feet (6.1 m). The seeds can live up to 18 months and can even grow under water.
Impatiens glandulifera can grow in both the shade and direct sunlight, though it tends to grow taller in shady locations. The plant can exist in almost any type of soil as long as it is very moist. While not impossible, it can be difficult to grow in areas that do not get a lot of rain.
When planting impatiens, a gardener should remember that the plant is essentially a noxious weed. For this reason, it can potentially take over a flower garden and suffocate the other plants. Impatiens glandulifera should be planted in a separate area of the garden to help prevent this from happening. Even with careful placement, however, it can still spread to other garden beds once it releases its seeds each year. The seeds normally do not have to be buried to take root, and can be easily transported to other areas of the yard on the soles of shoes or by animals.
It can be very difficult to control the spread of impatiens glandulifera. Preventative measures, to make sure that the plant does not overtake its surrounding, can be accomplished by pulling new plants up by the root. This is usually fairly easy because its root system is very shallow, typically going only 4 to 6 inches (10.16 to 15.24 cm) into the ground.
Unfortunately, impatiens glandulifera do not respond to herbicides, therefore its spread cannot be controlled using such products. Applying an herbicide can prevent the plant from flowering, however, which can, in turn, prevent the seed pods from developing. This method may not be desirable because it prevents the flowers from blooming, which is normally the reason a person adds the plant to garden in the first place.