Meet the plant
Himalayan Balsam (Impatiens glanulifera) is an attractive looking flower, with a stout, hollow stem, trumpet shaped pink/white flowers and elliptical shaped green leaves. It grows in dense stands and can be up to 2m tall. It has an explosive seed capsule, which scatters seeds over a distance of up to 7m.
It grows mostly on river banks and in damp woodlands.
It was introduced into Kew Gardens, and has spread via its seeds – both individuals passing on the seed to others for garden planting and seeds floating down rivers before becoming lodged in soft muddy banks and germinating.
Download the Himalayan balsam ID guide
Read more about Himalayan balsam
Himalayan balsam grows in dense stands and it shades out and crowds out many native species. It produces much nectar and therefore is attractive to pollinating insects, possibly to the detriment of native flowering plants (which are no longer visited by these insects and thus don’t get pollinated).
It dominates riverbanks, and in the winter when it dies back its shallow root system is no help in stabilising the bare bank, which is then at risk of erosion. Dense stands can also impede the water flow at times of high rainfall, increasing the likelihood of flooding.
Management of Himalayan balsam
The shallow root system means that Himalayan balsam is very easy to pull out of the soil by hand. This makes it a great activity for schools, groups and volunteers to get stuck into. We’ll be working with groups and volunteers to undertake much of our Himalayan balsam removal work.
The best time for removing Himalayan balsam is the summer, between May – July/Aug. The seeds only persist for around 18 months in the soil, so populations can be eradicated after 2 or 3 years of consistent control.
An alternative option for larger, monoculture stands of Himalayan balsam, on easily accessible level ground, is cutting using a strimmer or mower, before the plant sets seed. This is less labour intensive and a lot faster than hand pulling and we’ll be using this technique for larger stands.
We’ll be offering conservation volunteer days you can join in with to pull Himalayan balsam, these are a great fun way to get involved, get outdoors and meet new friends. Alternatively, we can facilitate this activity for existing groups.
Where is it?
Himalayan balsam is widespread and is found throughout our project area and in all our partner Fishery Trust catchments.