Over the past couple of days we have been at Hawthorn Dene removing Himalayan Balsam.
This invasive non-native species was introduced to Britain in 1839 as a garden plant, and by 1855 it had escaped gardens and was growing in the wild.
It tends to grow in dense stands that can out-compete native species. If not managed properly it can rapidly colonise riverbanks and areas of damp ground and cause particular problems in sensitive habitats. In autumn when the plant dies back, it can leave riverbanks bare of vegetation and vulnerable to erosion.
The generic part of the Latin name Impatiens means impatient, and refers to the means of dispersal of the seed, which is the key to the aggressive spread of this species. When the seed pods mature, they explode when touched, scattering the seed up to 7m away. Seeds are also spread by water and they may remain viable for up to two years.
The removing of this species at Hawthorn Dene is part of a long-term project by the National Trust to prevent it spreading and isolate it from the area as much as possible.
The method we were using was to simply pull out each individual plant by hand. Thankfully the plant has a shallow root system making this reasonably easy to do, though it is still a slow and time consuming process due to the extent of its coverage (there is a lot of it!).
Still, we have managed to clear a fair amount of the stuff so far and aim to clear some more before it starts to flower in June.