How do you keep slugs off your lettuce? Experts could soon discover the Holy Grail

One of our leading garden experts puts copper paint around the rim of his pots to deter them.

Others try anything from lines of salt to broken egg shells. But slimy slugs remain the bane of gardeners' lives.

Now for the first time, The Royal Horticultural Society (RHS) is undertaking a scientific study to see which methods really work - giving hope that we could finally keep slugs off our lettuces.

The RHS will test five common deterrents this summer and report the findings in autumn.

Alan Gray from East Ruston Old Vicarage gardens near Stalham said it would be interesting to see the RHS findings.

He recalled his grandmother's technique, saying: 'She used to use the soot from the chimney to deter slugs and it definitely worked, but you had to replace it each time it rained.

'Nowadays I use copper paint around the rims of my pots. It seems to work well.'

Mr Gray believed the best way to have a slug-free garden was to encourage other wildlife into it.

He said: 'Frogs and hedgehogs love ponds and they will automatically control the snail and slug population around it. The trouble with pellets is that people throw it around like confetti and other wildlife may consume it.'

Derived from the shelled mollusc, the majority of the 44 slug species in Britain today are shell free, and with few friends, hedgehogs and small children with muddy knees aside.

The former quite enjoy slugs, which are a vital part of a hedgehog's diet.

It is estimated that slugs cause around £8m in damage to farmers' fields annually.

? What method do you use to deter slugs? Email neil.didsbury@archant.co.uk