Cornwall Wildlife Trust has welcomed the recent decision to ban the sale of five invasive non native aquatic plants in the UK.

These are: • Floating water primrose (Ludwigia grandiflora, Ludwigia uruguayensis and Ludwigia peploides) • Floating pennywort (Hydrocotyle ranunculoides) • Parrot’s feather (Myriophyllum aquaticum) • Australian swamp stone-crop (Crassula helmsii) • Water fern (Azolla filiculoides)

The Trust says it has been battling against the problems caused across the county by these non-native species for many years, and while it is too late for some sites already infested with the likes of Parrot’s feather and New Zealand pygmy weed, there is still a lot which can be done to halt the spread of these plants into the wider environment.

A spokesman said that the government’s announcement is a promising first step in the right direction, and it is encouraging to see ministers taking such a strong stand, despite the ban not taking effect until April 2014.

Lisa Rennocks, invasive species project officer atb the trust, said: “I’m delighted at the decision to finally ban the sale of these five species. This action will most definitely help in preventing their spread into the wider environment.”

The trust says that non-native invasive plant species are one of the greatest current threats to the Cornish environment and its biodiversity, as they are often much more vigorous than our native species, and lack the natural pests and diseases needed to keep them in check.

It adds that invasive aquatic plants in particular out-compete native aquatic plants and can form dense mats, choking up watercourses, increasing the risk of flooding, deoxygenating water and limiting access. And that substantial amounts of money are currently being spent annually in managing non-native invasive species on our waterways, ponds and lakes.

Lisa continues, “I hope that the ban doesn’t prompt an influx of equally invasive alternatives or plant cultivars with the same invasive traits but slightly different names. It really can be difficult to know exactly what you are buying. We would urge anyone to seek advice from a reputable retailer if at all in doubt”.

“Pond owners should not panic if these plants have already become established in their garden pond. Simply having them in your garden is not an offence, but causing them to spread into the wider environment is potentially a criminal act. People should consider removing the plants as a part of their routine pond maintenance when it is least damaging to the wildlife, making sure to dispose of them carefully.”

The trust has advice for those keen to get rid of the foreign arrivals with most of these species able to be composted with the exception of flowering water primrose.

The trust says: "Remember to place all removed material onto a mat or tarpaulin by the edge of the pond and to leave it for a few days, by which time most of the plant will have began to desiccate. The barrier will prevent fragments from re-establishing in your garden while you provide time for any mobile creatures caught up in the process a chance to return back to the pond.

For more information and advice on ponds and how to care for them and their associated wildlife  visit www.erccis.org.uk/pondcheck.