Islanders asked to help find hidden pockets of ‘invasive plant’
There are fears that pockets of an invasive plant – which can spread quickly and out-compete native plants – are going undetected in Guernsey.
Thousands of Himalayan balsam plants have been removed over the last few years, in a bid to get in top of the problem.
Francis Russell from the ACLMS Non-Native Invasive Species Team said it had first found plants in 2020 and had since identified it in nine different locations across the island – from a rubble pile at Pleinmont to a planter near Les Gravees and a marshy area at the reservoir.
‘Most of the sites where we found this invasive plant were in people’s gardens, and it is quite possible that there are more places that we don’t know about,’ he said.
‘We rely on the public’s interest and support in reporting this and any other invasive species.’
It is unknown how the plant, which is native to Asia arrived in the island. It is not sold in garden centres, but Mr Russell said his team had a report that some seeds were brought in during the 1970s.
It could also have been spread through contaminated bird seed. Once introduced, it often spreads along water courses, but that does not seem to be the case in Guernsey, despite checks downstream of any plants found.
Mr Russell said his team had been checking any sites the plant has been found in following years to make sure any remaining seeds had not germinated.
‘It can very quickly spread,’ he said.
‘And we just don’t know how much more is out there.’
It had been thought the problem had been dealt with, but a recent picture shared with the Societe showed the plant in a local garden and there are fears it may be living hidden in other gardens.
It has attractive pink flowers, but it can grow up to two metres tall and smothers out other vegetation. It is an annual, but each plant can produce up to 800 seeds. These are dispersed with explosive seedpods, which can shoot seeds up to seven metres. Seeds are then viable for two years.
Mr Russell urged people who believed they had the plant to get in touch. They could then be given advice and the location can be recorded and checked. The plant can be removed, but should not be composted.
‘We are getting close to eradicating it, but we need to keep going,’ he said.
Acting while it is in the early stages of its invasion is critical. Once it takes over an area, removing Himalayan balsam can be a formidable task. At this time of year, the plants will be starting to develop seed pods, so islanders are encouraged to check their land and report any sightings before it can spread. A photograph would help.
Suspected sightings of Himalayan balsam should be reported by emailing aclms@gov.gg or calling 01481 220110.
