How do I treat slugs & snails?

Hunt at night with a torch. Twenty minutes twice a week is more effective than anything else. Iron phosphate pellets are effective and safe around pets and wildlife, unlike metaldehyde.

Will slugs & snails spread to my other plants?

No. Slugs & Snails does not spread from plant to plant — each affected plant developed it independently, usually from the same underlying conditions.

Slugs & Snails

Q: What causes slugs & snails?

Slugs & Snails is pest. Slug damage is easy to confirm because of the slime, which dries to a silvery trail visible in low light. They feed at night and in wet weather and hide during the day under pots, boards and mulch — which is also how you catch them.

Treatable

Pest · does not spread

Slug damage is easy to confirm because of the slime, which dries to a silvery trail visible in low light. They feed at night and in wet weather and hide during the day under pots, boards and mulch — which is also how you catch them.

What it looks like

Irregular holes with smooth rounded edges, chewed from the middle of the leaf as well as the margins, and a dried silvery slime trail across leaves or soil. Damage appears overnight and there is nothing to see by day.

How to confirm it

Silvery dried slime trails on leaves, pots or soil.
Smooth-edged holes, often in the middle of a leaf.
Damage appears overnight, especially after rain.
Go out with a torch an hour after dark and you will find them on the plant.

What to do

1Hunt at night with a torch. Twenty minutes twice a week is more effective than anything else.
2Iron phosphate pellets are effective and safe around pets and wildlife, unlike metaldehyde.
3Set out boards or upturned pots as daytime shelters, then collect what gathers underneath.
4Beer traps work but only over a very small radius.

What it gets confused with

One observation settles each of these.

Cabbage worms →

Caterpillars leave frass pellets and no slime, and the holes are more ragged.

Flea beetles →

Flea beetles make tiny round shot-holes, not large smooth-edged ones.

Preventing it next time

Water in the morning so the surface is dry by nightfall.
Keep mulch pulled back from the stems of vulnerable plants.
Clear hiding places near beds.

Plants affected

Lettuce & Greens Hydrangea Houseplants Basil

Check these two things first

Push a finger into the soil, two knuckles deep. Wet soil plus a wilting plant means too much water, not too little — and it is the commonest reason a plant is dying. Dry soil plus crisp leaves means the opposite. The leaves look nearly identical either way, so the soil is what tells you.
Turn a damaged leaf over. Half of all diagnoses live on the underside: fuzz means downy mildew, fine webbing means spider mites, clusters of insects mean aphids. Nothing on the top of a leaf is as informative.

Most garden problems are cosmetic and resolve without treatment. Reach for a spray last, not first.

Not sure it is slugs & snails? Run the diagnostic key →