Near Reepham, a woodland near Salle and a riverside path near Lenwade have already fallen to the invader – Himalayan balsam (Impatiens glandulifera).
 
This fast-spreading weed was first brought to this country in 1839 to adorn Victorian gardens, but has since spread out of control, threatening whole ecosystems.
 
Volunteers will be tackling the infestation at Green Lanes in early July, and additional help from local people is actively sought.
 
Himalayan balsam is an annual plant that regenerates from seed each year. Each plant can produce around 800 seeds that can be launched from exploding seedpods up seven metres from the plant. These can even survive and travel along watercourses, which means this species can easily spread along rivers and streams.
 
Each winter, the dense thickets die back, leaving river banks bare and susceptible to erosion and collapse.
 
Under the provisions made within Schedule 9 of the Wildlife and Countryside Act 1981, it is an offence to allow Himalayan balsam to grow in the wild or let its seeds infect neighbouring properties.
 
Local action against Himalayan balsam is being co-ordinated by the Norfolk Non-Native Species Initiative (NNNSI).
 
The plant forms dense stands of vegetation reaching 2–3 metres in height that shade out native plant species.
 
Volunteers from The Conservation Volunteers (TCV) are in the frontline of tackling this alien invasion, and they are keen for more local people to get involved in one-off action days to pull it up before it sets seed.
 
TCV team leader Mark Webster said: “Fortunately, it can be pulled up very easily, which means that almost anyone can make a big impact on its numbers in just a short time.”
 
Sightings of Himalayan balsam, which has a pink flower shaped like a policeman’s helmet, should be reported by email.
 
To join an organised event removing Himalayan balsam near Salle or Lenwade, please see the activity listings for details of when and where to meet.