Himalayan Balsam (Impatiens glandulifera, Royle.) is not a native species to the UK originating, as the name implies, in the Himalayas. Himalayan Balsam colonises areas rapidly and quickly outcompetes the surrounding vegetation and reduces diversity. Himalayan Balsam is an annual plant; growing from seed, flowering and setting seed within a year before dying. All Himalayan balsam plants germinate from the previous year’s seed. Himalayan Balsam grows very rapidly which necessitates readily available access to soil moisture which is why it has colonised river banks which have an abundance of moisture and nutrients. This causes a problem because Himalayan Balsam does not have an extensive root system and it is crowding out perennial plants that bind the river banks with their root systems. During flood events the river banks are then vulnerable to floodwater because of the lack of perennial plants. There are also claims that the height of the plant causes a problem by restricting the flow of the river.
Himalayan Balsam has been added to Schedule 9 by The Wildlife and Countryside Act 1981 (Variation of Schedule 9) (England and Wales) Order 2010: this means that it is illegal to plant or otherwise cause to grow Himalayan Balsam in the wild.
Himalayan Balsam is the tallest annual plant in the UK growing up to 3 metres in height a year. It has highly visible pink flowers on fleshy hollow stems that are green in the spring but become red as the year progresses. The elliptical leaves and side branches arise in whorls of 3-5 from stem joints. A distinctive characteristic of the plant are the seed capsules which provide its alternative name ‘Touch-me-not’ Balsam. The capsules open explosively when touched spreading the seeds up to 7 metres enabling the plant to colonies new areas. As an annual it has a very shallow root system, barely adequate for its tremendous height.
Cultural – Cutting, strimming or pulling on a regular basis for about three years will be effective and may even eradicate the plant from isolated sites.
Chemical – Himalayan Balsam tends to grow near water and therefore the selection of an appropriate herbicide is limited. Guidance notes for the use of herbicides in or near water have been published by the Environment Agency. Spraying needs to occur before the plant starts to flower but after the seed leaves have disappeared to ensure that all the plants available for germination can be controlled.
The ALS Contracts Team can be contacted on 01952 898518 or 01952 898519 for enquiries regarding Himalayan Balsam Control or email firstname.lastname@example.org