Focus on
Himalayan Balsam Impatiens
glandulifera
A significant proportion of the practical
work undertaken over the summer months by Volunteers at the Trust
has involved pulling, bashing, slashing and strimming Himalayan
Balsam. Hundreds of volunteer hours soon mount up, making this
ubiquitous plant worthy of further investigation.
Himalayan Balsam is easily identified by
its shallow roots, hollow-jointed stem, lance-shaped serrated
leaves, and of course its distinctive white-to-pink flowers,
resembling an old fashioned policeman's helmet. It grows up to
three metres in height in dense stands, shading out most other
ground vegetation. Its flowers produce a nectar prized by
bee-keepers and favoured by pollinators to the detriment of native
flora. As an annual, it dies back in winter leaving bare river
banks susceptible to erosion.
Distinctive Flower and seed
Pods
Himalayan Balsam is native to the foothills
of the Himalayas, and became naturalised after being introduced to
the UK in 1839. Today it is one of Britain's worst invasive plant
species, having successfully colonised most of the country. Each
plant's exploding seed pods can disperse up to eight hundred seeds,
which remain viable for up to two years. Plants prefer damp ground
and river margins which allow the seed to be carried even further.
As an alien species, there is a distinct lack of natural
competitors. Warwickshire has not escaped Himalayan Balsam's
proliferation, and it is common and widespread across the county,
including the Sowe and Tame Valleys.
A key priority for the Trust is the
mitigation of its threat to biodiversity on some of our wetland
reserves. Management options are limited because Himalayan Balsam
favours a riparian habitat. This generally involves manual removal
and composting on site which is carried out by our many committed
volunteers. The plants are pulled up by hand throughout the summer
months, prior to seed setting from August to October. So what have
our Volunteers got to say on the subject?
Are we winning the Balsam
Battle? Who knows? But year on year, it is getting smaller if not
less prevalent at Whitacre Heath. Two years ago, it grew to eight
foot. Now it's more like five foot. Is that winning?
Christine Rundle
Working at a plant nursery, I
can't believe that one day a customer asked me if we sell Himalayan
Balsam, to which the reply was obviously NO! After pulling Balsam
at Whitacre Heath and Stonebridge Meadows, I felt reasonably
offended. William
Newbury
Put a 1p bounty on every plant
and tell all the posh London Restaurants that it's really good in
salads. Derek Lill
Unquestionably, Himalayan Balsam provokes
debate and opinion. Non-native species, including Himalayan Balsam,
Japanese Knotweed, American Mink and Signal Crayfish are some of
the worst offenders, and represent a real and present danger to the
ecology of our wetlands. By giving up their time to remove this
invasive weed, volunteers are pivotal to maintaining, restoring and
improving some of our best wetland sites.
If you are interested in finding out more
about the Trust and our volunteering opportunities please contact
us on 024 7630 2912.
George Green
Wild Career Trainee, Living Landscapes