Gardeners can keep slug numbers under control using grapefruit skins and beer traps, according to Tom Brown, head gardener at West Dean Gardens. Writing in BBC Gardeners' World Magazine, Brown shared a three-step approach to managing the pest, which he describes as "relatively tricky to get large numbers under control, but persistence pays off."
Autumn conditions favour slugs
The article notes that "autumn rainfall coupled with mild temperatures can be the perfect conditions for slugs, causing damage to maincrop potatoes in the ground." Brown advises gardeners to "keep areas tidy around vulnerable crops, removing hiding places for these molluscs during the day."
He recommends using "grapefruit skins and beer traps until November to keep populations manageable," along with applying "slug-eating nematodes."
Natural alternatives to pellets
Despite their reputation, slugs and snails can benefit gardens. The RHS explains that they aid decomposition by feeding on dead leaves, dung, and even dead slugs, and they serve as food for birds, hedgehogs, and frogs. However, some species feed on living plants, which is why they are often seen as pests.
The RHS states it is "much better" to "learn to live" with slugs and snails, but if plants need protection, traps or biological controls can help. Traps include hollowed-out grapefruit rinds—orange or melon varieties also work—placed cut-side down, or jars half-filled with beer and buried in the ground. These should ideally be cleared each morning.
Biological control methods
The biological control method involves nematode products containing microscopic worms, also known as eelworms, which penetrate slugs' bodies and destroy them. The RHS warns against using slug pellets, including organic varieties, as they can harm other garden wildlife. Instead, it recommends attracting natural predators or adopting the strategies outlined above.
