Waterways across the West Midlands are at threat from an invasive weed that is spreading rapidly in parts of the West Midlands, the Government has warned.

The Department for Environment, Food and Rural Affairs has warned that floating pennywort, often found in garden ponds, is threatening to be a major problem for river users and wildlife in Staffordshire.

A Defra spokesman said: “It has been present in the canal system for some time but recently crossed into the river system and has been found on the River Trent and some of its tributaries.

“Earlier this year the Environment Agency successfully treated a large area of weed near Burton which has led to the pennywort dying back. Similar measures are now being taken at Tamworth to control the plant’s spread on the River Tame.”

Experts said the release of a tiny fragment of pennywort can create a population that can choke an entire waterway, cause damage to the natural environment and cost the economy millions.

Defra has launched the second phase of the Be Plant Wise campaign to raise awareness of the damage caused by invasive aquatic plants at a time when pond owners may be thinking about tidying their ponds ready for winter.

It said the problem can be heightened at this time of year when gardeners may unknowingly assist the spread of harmful plants by disposing of unwanted pond plants inappropriately.

Launching the second phase of the campaign Environment Minister Richard Benyon said: “It’s important we raise awareness and encourage pond owners to be more plant wise at this time of year when they are starting to think about tidying their ponds. If everyone carefully disposes of unwanted pond waste this will help prevent invasive plants spreading to the wild."

More information on the Be Plant Wise campaign is at www.direct.gov.uk/beplantwise.