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Notebook · Guide 1 October 2026 · seasonal

Slugs and snails: what actually works (and what the research says doesn't)

Copper tape, eggshells, grit and wool pellets didn't reduce slug damage in RHS trials. What does help: torchlight patrols, protecting seedlings, morning watering, nematodes and predators.

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A garden at dusk with a torch beam lighting up a slug on a hosta leaf and a snail on a lettuce.
1The torchlight patrol: slugs and snails come out on mild, damp evenings.

Slugs and snails cause more gardening frustration than almost anything else, and they've spawned a whole aisle of products. The honest starting point comes from the RHS: some feeding is normal, and they can't and shouldn't be eradicated. They're food for birds, frogs, toads, hedgehogs and beetles. The goal is to protect the plants that matter — seedlings, hostas, lettuce and young veg — not to wage war on the whole garden.

In pictures

  1. A clear plastic cloche over a young lettuce seedling in a vegetable bed.
    2A cloche protects young seedlings.
  2. A two-panel contrast: on the left a ring of copper tape and crushed eggshells around a hosta, still nibbled, with a cross; on the right a gardener's hand picking off a slug by torchlight.
    3Copper and eggshell barriers didn't work in RHS trials (left); hand-picking does (right).
  3. A garden pond edge with a frog, a ground beetle and a hedgehog nearby among plants.
    4Frogs, ground beetles and hedgehogs all eat slugs.

01What the research says doesn't work

An RHS trial in realistic garden conditions found no reduction in slug damage from barriers made of:

  • copper tape
  • bark mulch
  • crushed eggshells
  • sharp grit
  • wool pellets

02What does help

  1. Torchlight patrols. Go out on mild, damp evenings with a torch and pick them off.
  2. Water in the morning, not the evening, so the surface is drier when slugs are active.
  3. Protect seedlings. Use cloches over young plants, or grow seedlings on to a bigger, tougher size before planting out.
  4. Traps. Sink jars of beer half into the soil — leave the rim a little above ground so beetles don't fall in — or lay upturned grapefruit halves. Check and empty them daily.
  5. Grow less tasty plants. The RHS lists many slug-resistant plants, including acanthus, achillea, agapanthus and fuchsia.
  6. Encourage predators — a pond for frogs and toads, log piles, and a garden that hedgehogs can get into.

03Nematodes

A biological control containing the nematode Phasmarhabditis hermaphrodita infects slugs in the soil. It needs the soil at 5–20°C and moist but well drained, and works best applied in the evening from spring to early autumn. It's unlikely to affect snails.

04Slug pellets

The RHS now advises avoiding slug pellets, including the ferric phosphate type sold as "organic", because of their effect on wildlife. Metaldehyde pellets have been banned for outdoor use in Great Britain since 31 March 2022, to protect birds and mammals.

Save your money
Skip copper tape, eggshells, grit and wool pellets. The trial found they made no difference.
A torch and a bucket cost almost nothing.
Protect only what matters. Most mature plants shrug off some nibbling.

How we checked this

Every care and safety claim on this page is verified against horticultural and veterinary sources.

Sources: RHS — Slugs and snails · RHS — How to stop slugs and snails: what works? · RHS — Snails · GOV.UK — Outdoor use of metaldehyde to be banned

Checked 1 October 2026. If our advice ever conflicts with the RHS, believe them and tell us.