Scientists are testing a selection of home remedies for deterring snails and slugs.
The RHS will use lettuce as a bait at the research facility at Wisley Gardens to try out the effectiveness of copper tape with a serrated edge, sharp horticultural grit, wool pellets, pine bark mulch and crumbled egg shells.
Dr Hayley Jones, entomologist at the RHS, says that gardeners swear by the success of their home remedies but until now there have been no formal studies to evaluate their claims.
Other remedies include putting plants in pots and raising them on bricks, smearing vaseline around the lip of the pots and the time-honoured beer trap. These are made by cutting the bottom inch or so off a plastic bottle or yoghurt pot, sinking it into the soil with only about one centimetre remaining above ground and filling the pot with beer. While it is cheap and effective those who are slug phobic will find getting rid of the slimies after they have succumbed can be unpleasant.
Probably the best organic slug and snail killing method is to buy nematodes through the post. Add these microscopic worms to water and use a watering can to spread them around in the early morning or at dusk, because they are light sensitive. The nematode ejects bacteria inside the pest’s body, which cause blood poisoning and death. The nematode then eats the remains, while searching for a new host. The worms have the advantage of being specific to the target pest, so other wildlife is not harmed. Also they are invisible to the human eye – a great benefit for the squeamish gardener.