The release of just a tiny fragment of plant can establish a population that can choke an entire waterway, causing damage to the natural environment and costing the economy millions. 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. By ensuring unwanted plants are composted properly and waste pond water is disposed of carefully away from streams, rivers, ponds or lakes, gardeners can help protect the environment and save the nation money.

In the South West, invasive species have been discovered in North Cornwall, the Somerset Levels and Studland in Dorset. (See Case Studies)

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. Many retailers are already taking steps to ensure people know what they’re buying and advising customers on how to dispose of unwanted pond waste properly.

“Making sure that ponds and rivers are cleared properly has real benefits to our natural environment. We must prevent the spread of these plants so that our rivers and wildlife can thrive and remain a safe and enjoyable place to visit.”

The Be Plant Wise campaign highlights five of the worst offending invasive aquatic plants that are threatening our wildlife and waterways. Plants such as floating pennywort, New Zealand pigmyweed, water-primrose, parrot’s feather and water fern can be found in your garden pond. Parrot’s feather is now adapting to the UK winters by becoming more frost resistant and water fern can readily colonise areas of freshwater, growing at great speed, doubling in size every two to three days.

Floating Pennywort is being found at an increasing number of sites in North East London, near the Olympic site along the River Lee and the River Roding, and also on the River Wandle in south west London. It is the most expensive of all aquatic weeds to control and the Environment Agency estimate they spent £510,260 on controlling approximately 300 km of it in 2009. It spreads quickly in spring and summer when it dominates the surface of the water, often covering it completely and blocking out oxygen and light for the flora and fauna beneath.

Pond owners are advised to:

· Compost with care – make sure you dispose of the whole plant properly and no fragments break away; dispose of waste pond and fish tank water away from streams, rivers, ponds or lakes;

· Stop the spread – be careful not to introduce invasive species into the wild, even accidentally, as you could be breaking the law; and

· Know what you grow – pick the right plants for your pond and manage them carefully. Choose non-invasive species where possible.

Be Plant Wise Case Studies – South West:

Little Sea, Studland, Dorset:

This is one of the most pristine lakes in lowland England and is within a National Nature Reserve. It has extremely important plant and animal life, including many national rarities and is owned by the National Trust.

Crassula helmsii was discovered in the neighbouring Eastern Lake. The National Trust has joined with Natural England and volunteers to try and control it and to stop it getting in to Little Sea but it was found in Little Sea about three years ago, along with large quantities of Nuttall’s water weed.

The Trust have carried out detailed canoe surveys, installing black plastic mats and digging it out, but it continues to spread. It is now becoming semi-terrestrial and going in to mires and marshes and smothering rare plants. It is growing amongst reeds and willow where it is very difficult to manage.

The trust are part -funding a Phd student to look at ways of managing it, and buying a boat to gain access to the areas.

It is unclear how Crassula and Nuttall’s water weed got to Little Sea but it maybe deliberate dumping of water weeds or even brought over on duck’s feet or by Sika deer. Flooding and wind can then spread it further.

Somerset Levels:

The Environment Agency discovered Water Hyacinth and Water Cabbage on a 500m stretch between the M5 motorway and Dunball Sluice, at King Sedgemoor Drain, which they believe were introduced to the waterway by a careless homeowner clearing out their aquarium or garden pond.

The Agency had to mechanically remove the plants to prevent them spreading to nearby lakes and rivers.

‘The discovery of two invasive plants is surprising. You might find one alien growing on a waterway, but two in close proximity suggests they were introduced at the same time by someone clearing out their pond. Probably someone living locally. Disposing of alien plants in this way is highly irresponsible,’ said Andy Baines for the Environment Agency.

Enfield Park, Camelford, Cornwall

Pond Check, a Cornwall Wildlife Trust initiative, joined forces with Friends of Enfield Park Conservation Group in Camelford in September to help clear-out invasive water weeds choking up the park’s pond. Nicola Morris, a recent zoology graduate from Newquay College and resident of Camelford, first contacted Pond Check after hearing about the project at college.

Pond Check is a free service aiming to raise awareness of the threat of non-native plants that are invading our ponds and waters. The scheme aims to help the public identify the worst pond invaders, which pose a threat to the environment and biodiversity.

Lisa Rennocks, co-ordinator of Pond Check for Cornwall Wildlife Trust, said: “We waited until the autumn to remove the weeds to minimise the impact on the resident wildlife. With the help of local community members we spent a day removing a significant amount of vegetation, all of which was disposed of on the compost heap which will benefit the park once composted down”.

For more info: beplantwise