Himalayan Balsam (Impatiens glandulifera) is native to the Western Himalayas and was introduced as an exotic plant in the mid 19th century. It is the tallest annual plant found in Ireland or the UK and can grow to between 2 and 3 metres in height. The stems are green to red in colour, hollow, brittle and jointed. Branches arise from the stem joints. The leaves are narrow dark green often with a red midrib and have toothed edges. Leaves can be 15cm long and are opposite or occur in whorls of three. The flowers are pale to dark pink and are carried on long stalks during the June to October period. A plant can produce well over 500 seeds, which are spread from shattering seed pods to distances of 5m or more. Each pod can hold up to 15 seeds. The seeds, which are also transported by water, can remain viable for up to 2 years. For this reason the plant has rapidly colonised river banks, excluding native species by competition. Colonisation of river catchments can cause a deterioration in the ecological status of waterways under the Water Framework Directive. As the plant is an annual, control methods are largely dependent on the prevention of seeding. Cutting to ground level in early summer with a billhook can prevent seed production, but cutting too early or pulling up whole plants may result in the re-growth of plants with flowering heads that have an even greater number of seeds. Cut material needs to be removed from the infected area and disposed of appropriately.
Himalayan Balsam is listed as an invasive weed in the Control of Aquatic Invasive Species and the Restoration of Natural Communities in Ireland (CAISIE) – European Commission Life+ Programme.
It’s an alien plant invasion – 21/07/2013
Himalayan Balsam flower causes havoc to countryside – 31/08/2014
If you have a problem with invasive weeds in your local authority area, on club grounds or a private property that you manage, call us for professional assistance and service.