Himalayan Balsam - Horley Conservation Group wages war on this pest Summer 2018

Himalayan Balsam introduced in 1839 was first cultivated as a greenhouse annual by gardeners. Nearly 200 years later it has been so 'successful' that it is choking the life out of our riverbanks and hedgerows

Posted on Aug 27, 2018

H. Balsam introduced in 1839 was first cultivated as a greenhouse annual by gardeners. It is also known by other less common names amongst which are “Kiss me in the Mountains” since this is where it originates from and also “Policeman’s Helmet” because of the shape of the purple flower it produces.

 

During the early summer months Horley Conservation Group one many voluntary groups is out busy trying to halt the advance of this non native plant by “Balsam Bashing” before the dreaded seeding period.

The largest annual plant in Britain, growing up to 2.5m high from seed in a single season. Himalayan balsam spreads quickly as it can project up to 800 seeds from a single plant up to a distance of four metres. Many seeds drop into the water and contaminate land and riverbanks, downstream and upstream because of the explosive nature of its seed release.

Commonly found along riverbanks and streams, around ponds and lakes, in wet woodlands and in ditches and damp meadows. It spreads quickly and forms dense thickets, altering the ecological balance and character of wetland habitats. The thickets out compete our native plants.

The plant produces a lot of pollen over a prolonged season and is attractive to pollinating insects. There is concern that its presence may therefore result in decreased pollination for other native plants.

It is recommended that the plants that are shallow rooted are pulled out and composted before seed is set. If this is done on a regular basis the plant will eventually die out.

A voluntary driven Conservation Group in Horley we are part many small armies trying to combat the advance of this invasive foreigner. We are working on the River Mole and Burstow Stream in our area to “Balsam Bash”.

Working on the Burstow Stream in this instance along the route of the Riverside Chain on the boundary of a new housing development will help to maintain the integregrity of the banks and preserve a valuable amenity for the local community to enjoy. Waders purchased through sponsorship of our group allow you to see evidence of bank collapse from within the stream due to the shallow root system of the weed, resultant fallen fencing and barbwire strands.

A call for help to the local Doggy Walkers Social Group helped in this task to stop the spread of this invasive weed along the stream and further into the meadows we enjoy. Hopefully this enthusiasm can be maintained to rid the invader in our vicinity over the coming years.

This species is listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales therefore; it is also an offence to plant or otherwise cause to grow these species in the wild.

 Identification Features

  • The hollow, succulent stems hollow like celery are purple tinged and smooth.
  • The serrated, pointed leaves are arranged in pairs, or three to a node; they are mid green with a pinkish mid-rib and about 12 to 16cm long.
  • Roots shallow bulbous with nodules.
  • Flowers Pink/Purple rarely White.