Pests & diseases
Slug & snail
Also known as: snail
Soft-bodied molluscs that feed at night and can shred seedlings and leafy crops, especially in warm, damp weather.
Slugs and snails are among the most common — and most disheartening — problems a new UK grower meets. They are soft-bodied molluscs that rasp away at plant tissue with a tiny, file-like tongue, leaving irregular holes in leaves and the tell-tale silvery slime trails that give them away. Snails carry a coiled shell and tend to shelter in walls and rockeries; slugs have no shell and can burrow down into the soil, where some species attack roots and potato tubers from below. Both thrive in Britain's mild, wet conditions, which is why they're such a year-round nuisance here.
The damage they do
The real heartbreak is seedlings. A tray of hardening-off lettuces, beans or courgettes that looked perfect at dusk can be reduced to bare stalks by morning, because slugs feed mostly at night and in wet weather. Tender young growth is most at risk, so the danger window is greatest in spring and early summer when everything is small. Established plants usually shrug off a little nibbling, but soft crops like lettuce, hostas, brassica seedlings and strawberries stay vulnerable all season. Outright loss of newly planted seedlings is the single biggest reason beginners give up on a crop too soon.
Wildlife-safe control
The good news is that you don't need anything harsh. The most reliable long-term approach is to encourage natural predators: hedgehogs, frogs, toads, ground beetles, slow-worms and thrushes all eat slugs and snails, so a small pond, a log pile and a few wild corners do more than any single product. Many of these predators also help with aphids and other pests, so a wildlife-friendly plot pays off broadly.
Alongside predators, the practical front line is barriers and traps:
- Hand-pick after dark. A torch on a damp evening, collecting slugs and snails into a tub, is unglamorous but genuinely effective — especially early in the season before numbers build.
- Barriers around vulnerable plants. Copper tape, sharp grit, crushed eggshell or wool pellets all deter molluscs from crossing to your seedlings.
- Beer traps. A sunken pot of beer drowns them overnight; empty and refill every few days.
- Biological nematodes. Watered onto warm, moist soil from spring, the microscopic nematode Phasmarhabditis hermaphrodita (sold in the UK as Nemaslug) infects slugs underground and is completely safe for pets, children and wildlife.
A note on slug pellets
Older blue slug pellets contained metaldehyde, which was banned from sale and use in Great Britain in 2022 because of the harm it caused to birds, hedgehogs and pets. If you still have any in the shed, dispose of them safely and don't use them. The pellets sold today are based on ferric (iron) phosphate, which breaks down into the soil and is approved for organic gardening — far kinder, though even these are best used sparingly alongside the methods above.
For a full plan, see our guide to slugs and snails.
In a UK garden
In the UK's mild, damp climate slugs and snails are active for most of the year, with the worst damage on warm, wet spring and summer nights and in shady, sheltered allotment plots.
Example
Young lettuce or bean seedlings that vanish overnight, leaving ragged holes and silvery slime trails across the soil and leaves, are the classic sign of slugs and snails.