The Ornamental Aquatic Trade Association (OATA) is calling for consumers to be made more aware of the issue of invasive species, following a ban on five aquatic plants.
The non-native invasive water plants will be banned from sale in England and Wales in April 2014 - the first time non-native plants have been banned from sale in England. Retailers have a year to transition to the ban.
Defra puts the cost of eradicating the current outbreak of water primrose, one of the banned plants, at £73,371. Based on what happened in Europe and the USA, it warned that should the plant became widespread in the UK costs could increase significantly, reaching £241.9m.
OATA chief executive Keith Davenport said the association has advised members to dispose of the plants now and stop selling them. He added that the economic effect is likely to be limited.
"We've been advising members not to sell some of these species for more than a decade," he said. "I would hope the effect will be marginal because we've been advising people not to sell them for so long. If it is in some cases that's unfortunate but it was a necessary move."
He said while banning the five plants is the right thing to do, further bans should be unnecessary. "There has been no resistance from us on these five but with any further species we would be increasingly critical. A lot of invasive species are a problem because people are not aware of the issue. We need to stop people dumping plants in the wild.
"Any plant that's not in the garden pond, the aquarium, a green bin or in a compost bin should be there. It's unacceptable anywhere else. We've got to get the message out and there is no excuse for any business not to get behind Be Plant Wise."
The campaign, which launched by Defra and the Scottish Government to raise awareness, is supported by the OATA, the HTA, the RHS and wild-plant conservation charity Plantlife.
Plantlife and the Wildfowl & Wetlands Trust (WWT) are urging members of the public to avoid the plants if they see them for sale. WWT head of conservation policy Carrie Hume said there are native alternatives that could be sold instead. "British varieties like marsh-marigold or yellow iris are just as beautiful and will help to attract native wildlife," she added.
Non-native invasives - The banned list
The five non-native invasive plants that will be banned from sale in England and Wales in April 2014 are:
Water primrose - Ludwigia grandiflora, Ludwigia peploides and Ludwigia uruguayensis
Parrot's feather - Myriophyllum aquaticum
Water fern - Azolla filiculoides
Floating pennywort - Hydrocotyle ranunculoides
New Zealand pygmy weed - Crassula helmsii.