ROADS and pavements in the county are under threat from an illegal plant.
Japanese Knotweed was introduced to Britain in the 19th Century as an ornamental plant.
But the speed of its growth and the damage it causes resulted in it becoming an offence to plant Knotweed in the wild.
Knowtweed can grow up to 10cm a day and causes havoc below concrete and tarmac as it forces its way through the surface, resulting in cracks that damage roads and buildings.
Sussex Wildlife Trust said a recent clearance of Knotweed was estimated to have costs £40,000 for six square yards.
Knotweed grows wild in Rye on the slopes beneath the Gungarden and Watchbell Street.
DEFRA guidelines say if you have the plants on your premises it is your responsibility to stop their spread into the wild.