Knocking off Policeman’s Helmet 2


This Sunday’s task is pulling up Himalayan Balsam at Shotover Country Park, but why is this such an important thing to do?

Himalayan Balsam (Impatiens glandulifera) is an invasive species that was originally introduced to the UK in 1839 as a hot house and warm garden plant famed for its prodigious growth. This meant the ordinary person could afford to buy the seeds, rivalling the expensive exotic flowers cultivated by the rich in their greenhouses (Wikipedia, 2014). Indeed, the plant came to be commonly known as ‘Poor-man’s Orchid’. It produces clusters of purplish-pink helmet-shaped flowers which have led to some of its many other common names:

  • Policeman’s Helmet
  • Bobby Tops
  • Copper Tops
  • Gnome’s Hatstand
  • Beebums
Himalayan Balsam flowers

Himalayan Balsam flowers. Photo by ceridwen from Wikimedia Commons

Unfortunately, Himalayan Balsam soon escaped the gardens and greenhouses of Britain and has been causing problems for native plants and habitats ever since. There are many reasons why the task of removing it from nature reserves and country parks is extremely worthwhile:

It grows well in low light, meaning it shades out other plant species and causes the degradation of habitats by killing off almost everything else (Royal Horticultural Society, 2014).

It also likes to grow in wetter ground, such as along river banks, but it dies back in the Autumn leaving the banks of rivers exposed and prone to erosion (CABI, n.d.). It seeds remain viable for up to two years, so when they enter into the catchment of a river they can be easily and widely spread downstream (Royal Horticultural Society, 2014).

Himalayan Balsam growing tall

Himalayan Balsam, Lochwinnoch. Photo by wfmillar from Wikimedia Commons

Its species name glandulifera comes from the Latin glandis (gland) and ferre (to bear) as the plant has glands that produce plentiful sticky, sweet nectar (Wikipedia, 2014). This means that bees pollinate it in preference to native plant species (Randall, 2013).

To top it all off, Himalayan Balsam can grow to between 2-3 metres tall and it produces seed pods that explode when disturbed (Royal Horticultural Society, 2014), hence its other Latin name, Impatiens (impatient) and its common names, Jumping Jack and Stinky Pops. The seed pods can hold up to 800 seeds and explosively disperse them up to seven metres away! (Royal Horticultural Society, 2014).

It is easy to see why Himalayan Balsam has been listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales, meaning it is an offence to plant or otherwise grow this species in the wild (Plantlife, 2010).

Getting rid of Himalayan Balsam is not easy. It has been estimated that it could cost up to £300 million for its total removal (Randall, 2013). This is why laboratories at CABI in Surrey have been investigating biological solutions (CABI, n.d.). They have discovered a rust fungus that seems to attack only the Himalayan Balsam and no other plant (Randall, 2013).

But do not despair, large sums of money and scientific research are not the only way…there is hope for OCV foot-soldiers in this fight. The good news is that the roots of Himalayan Balsam are very shallow, so small infestations can be effectively controlled by hand pulling. As the seedbank lasts for about 18 months, two years of management could eradicate the plant in a small area (Centre for Ecology and Hydrology, 2004). The ideal time for Balsam pulling is before the seed pods develop after flowering in June to August – so RIGHT NOW (get to it OCVers)!

The vital work we do at Shotover Country Park this Sunday to pull up Himalayan Balsam in a specific area will help the Council to assess the most efficient methods of control. If all else fails, we can resort to eating it, as all parts of Himalayan Balsam are edible. Try cooking the seeds into a curry to give it a nutty flavour.

 

References:

CABI (n.d.). ‘Himalayan balsam is a highly invasive annual weed’. http://www.cabi.org/uploads/projectsdb/documents/1352/himalayan%20balsam_lr.pdf [Accessed 24 May 2014].

Centre for Ecology and Hydrology (2004). ‘Information Sheet 3: Himalayan Balsam’. http://www.ceh.ac.uk/sci_programmes/documents/himalayanbalsam.pdf [Accessed 24 May 2014].

Plantlife (2010). ‘Himalayan Balsam’. http://www.plantlife.org.uk/wild_plants/plant_species/indian_himalayan_balsam [Accessed 24 May 2014].

Randall, D. (2013). ‘Himalayan balsam: Call the Marines! It’s an alien plant invasion’. The Independent. Sunday 21 July 2013. http://www.independent.co.uk/news/science/himalayan-balsam-call-the-marines-itsan-alien-plant-invasion-8723024.html [Accessed 24 May 2014].

Royal Horticultural Society (2014). ‘Himalayan Balsam’. http://www.rhs.org.uk/advice/profile?PID=480 [Accessed 24 May 2014].

Wikipedia (2014). Impatiens glandulifera. http://en.wikipedia.org/wiki/Impatiens_glandulifera [Accessed 24 May 2014].


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2 thoughts on “Knocking off Policeman’s Helmet

  • Ian Brown

    Pulling Himalayan Balsam, a great task and, if completely removed, it can be got rid of in one year as the seeds usually have 100% germination. Expect a crop of nettles and Cleavers next year, because of the enriched soil, but annual mowing should reduce the fertility and the new growth should prevent the return of the Balsam. With a little luck, a diverse meadow will result; after many years of hard work.