Slugs have won, RHS says, as home remedies fail tests

Gardeners wasting their time with grit, copper tape and eggshells to protect prize plants, study shows

EVERY serious gardener has their own remedy for slug infestations, whether it is coffee grounds, copper tape or eggshells.

However, scientists have found that they are all wasting their time. Short of slipping out at dusk with a pair of scissors or resorting to chemical control methods, there is no way to defeat the invaders.

The Royal Horticultural Society (RHS) tested five home remedies on their lettuces over the summer, to see which provided the best defence.

The scientists found copper tape, horticultural grit, pine bark mulch, wool pellets and egg shells made no difference when applied around lettuce, with the gastropods inflicting the same damage to those treated with the remedies as without. They sowed 108 lettuces at the John Macleod Field Research Facility in Wisley, Surrey, and treated them with alternate control methods – including no control at all – and found no discernible difference between those with no deterrent and those that used a home remedy.

Dr Hayley Jones, an entomologist at the RHS and the lead researcher, said: “Our study reveals that many gardeners could be wasting time and money by turning to home remedies in a bid to protect their prized plants. With the likes of egg shells, barks and mulch so far proving no discernible deterrent to slugs and snails, we would recommend using proven formulas like nematode biological control if the damage is just too much to bear.”

Those tested were thought not to work because, although rough and sharp textures look unattractive to soft-bodied animals, the thick mucus of slugs and snails acts as a protective shield, enabling them to glide over.

A toad, however, may be the answer to slug woes, as the RHS recommended that gardeners encourage predators to guard their plants. Physical removal and traps also proved effective.

Jack Wallington, a landscape designer and The Telegraph’s gardening columnist, said: “The findings are really disappointing. Often it feels like slugs and snails are winning the war on our plots. Barriers like eggshells have never worked for me either but copper tape I find surprising as it appears to protect my hostas in pots. My hopes now fall on the frogs I encourage in a micro wildlife pond on my allotment.” One popular home remedy that is yet to be tested is beer, but it will not form part of the study. Dr Jones said that while no “real scientific studies” had been done on beer and slugs, it was an area of interest.

Records in the RHS Lindley Library show the war between gardeners and gastropods has been raging for centuries. Texts show that home remedies have been used since the 1600s to counter slugs and snails – with presumably as little success then.