DEFRA is reviewing schedule nine of the Wildlife & Countryside Act 1981 and is considering banning sales of some invasive plants.
Proposed additions to a list of plants banned from being planted or released into the wild include Cotoneaster, Crocosmia and Rosa rugosa. A more restricted list recommends banning sales of Rhododendron ponticum, Gaultheria shallon and eight aquatic plants.
Hampshire-based Rhododendron grower John Middleton, of Shelley Common Nursery, said the revised lists would affect his business. "All the hardy rhododendrons sold in the UK originate from R. ponticum. Half the plants I sell are rhododendrons. Banning their sale would mean the loss of varieties."
HTA president Andrew Richardson said: "We were assured it is not the final list. As it stands it's knocked out 60 per cent of the top 10 plants sold in the UK by including those such as Cotoneaster."
DEFRA needs to control invasive non-native plants as they are the second-greatest threat to wildlife and can damage land.
The cost of eradicating Japanese knotweed nationally so far is estimated at £1.56bn, and £45m has been spent on removing Rhododendron from Snowdonia National Park.