How to Get Rid of Slugs and Snails in the Garden

You planted seedlings in the evening, and by morning there's nothing left but stumps and a silvery trail. Slugs and snails do more damage in most gardens than every insect pest combined — a single slug can eat around half its body weight in a night, and they work invisibly while you sleep. The good news: a combination of two or three of the methods below will protect almost any garden. The bad news: several of the most famous home remedies do essentially nothing.

Know your enemy

Slugs and snails are nocturnal and moisture-dependent. By day they hide anywhere cool and damp — under pots, boards, dense mulch and leaf litter — and they lay clusters of pearly eggs in moist debris. Damage peaks in mild, wet weather, which is why a rainy week in spring or autumn can devastate a bed of seedlings. Ragged, irregular holes in leaves plus slime trails is the diagnostic combination; if there are holes but no slime, look for caterpillars or beetles instead.

Step 1: make your garden less slug-friendly

• Clear boards, brick piles, dense weeds and fallen leaves near vulnerable beds — every one is a daytime slug hotel.
• Water in the morning, not the evening, so the soil surface is dry by nightfall when slugs come out. Drip irrigation helps for the same reason.
• Keep mulch a few centimetres shallow and pulled back from plant stems.
• Thin crowded plantings so air moves and the soil surface dries faster.

Step 2: physical defences that actually work

Copper tape around pot rims and raised-bed edges gives slugs something like a mild electric shock — their slime reacts with the metal — and it genuinely deters them as long as the band is wide, clean and unbridged by leaves. Wool pellets and food-grade diatomaceous earth create scratchy barriers slugs dislike crossing; both need topping up after heavy rain. Hand-picking sounds medieval but is ruthlessly effective: go out an hour after dusk with a torch twice a week and drop what you find into soapy water. Numbers collapse within a fortnight.

Beer traps work — slugs genuinely are drawn to yeast — but only within a metre or so, and they need emptying and refilling every couple of days. Use them to protect one prized bed, not the whole garden. Sink the trap with the rim a centimetre above soil level so ground beetles, which eat slug eggs, don't drown in it too.

Step 3: pellets — the safe kind

Iron phosphate pellets are the modern, organic-approved slug bait: slugs eat them, stop feeding and die within days, and the leftover pellets break down into soil nutrients. They're considered safe around pets, birds and hedgehogs when used as directed, and they keep working after rain.

Warning: avoid old-style metaldehyde slug pellets. They are seriously toxic to dogs, cats, birds and hedgehogs, and have been banned for garden use in several countries, including the UK. If a product doesn't say iron phosphate (or ferric phosphate) on the packet, leave it on the shelf.

Step 4: recruit the predators

A garden with birds, frogs, toads, ground beetles and hedgehogs has a permanent night shift working for free. A small pond, a log pile in a quiet corner and skipping pesticides on the lawn all raise your predator count. For a targeted biological option, nematodes (Phasmarhabditis hermaphrodita) watered into warm, moist soil control slugs underground for around six weeks — they're invisible, silent and harmless to everything else.

Step 5: plant strategically

Slugs have strong preferences. Hostas, dahlias, delphiniums, lettuce, basil and young bean plants are magnets; lavender, rosemary, sage, hardy geraniums, ferns, astilbe and foxgloves are almost never touched. Put the magnets where you can defend them — in pots with copper tape, or one guarded bed — and let resistant plants hold the exposed ground.

What doesn't work

Tip: on a warm, damp morning, lift every pot, board and stone near a damaged bed. You'll usually find the culprits clustered underneath — the fastest cull you'll ever do.

If you're not sure whether slugs or something else is shredding your plants, photograph the damage with PlantMe. The app tells slug and snail feeding apart from caterpillar, beetle and disease damage, and suggests the right counterattack.