Slug and snail damage in the garden.

One of the biggest pests in the garden. Whilst they do a great job of breaking down vegetable matter where it doesn't seem to matter, they always seem to first go for the prized garden specimen plant or seedlings that we've been nuturing for weeks.

Table: Slug and snail problems and possible solutions for reducing their number and the damage they do.
Insect Symptoms Suggestion
Slugs and snails General damage to new shoots and plants. Slugs and snails are particularly fond of salad crops and fleshly leaved plants such as hosts, sunflowers, nicotiana and rudbeckia, often whole leaves disappearing overnight.

The small brown-grey garden slug, Arion hortensis causes the most damage to plants in the garden. They hide in the holes in the bottom of pots and the small gaps between pots during the day and feed at night.

The garden snail (Cornu aspersum syn. Helix aspersa is the most common snail found in British gardens, it can produce 300-400 young per year. They are quite easily picked off of plants and lightly crushed under foot, leaving the remains for blackbirds and thrushes to eat.

The keel slug Tandonia budapestensis, eats the roots of plants in particular potatoes. Use nematode control in spring, or grow a slug resistant variety like Kestrel.

Slug damage early in the plants growing cycle can kill the plant. So it's important to protect young plants from slugs and snails as soon as the weather starts to warm up or when you start to notice new shoots starting to appear.

Slugs don't like travelling over sand, gravel or egg shells they also don't like soot or the caffeine in coffee grounds. Spread the soot or grounds around the base of tender plants. Soot can be an irritant to the skin and eyes, so wear gloves and don't use soot around edible crops as it may be carcinogenic. The fresher coffee grounds, the more effective they are, but the grounds are acidic, so try not to add too many in one place at a time.

Use slug pellets when the ground has started to warm up and the soil is damp. Traditionally slug pellets contained metaldehyde, but care should be taken when using metaldehyde as it is toxic to dogs and cats (manufacturers do add a bitter tasting ingredient, Bitrex, to their slug pellets, to reduce the chance of accidental ingestion). If you are growing organically, then use pellets containing ferric phosphate instead, these are considered safer around animals and children, although care with application and storage of containers should always be considered. On edible crops pay particular care that pellets don't fall between leaves or stay in contact with leaves. Effective cover varies with different manufacturer's pellets, so check the back of the packet for dosage and don't over spread. If you use slug pellets, put them under a roof tile to keep them dry and stop them from blowing away.

Salt will kill slugs, turning them into a gooey mess, but salt will also kill any plants, so don't apply it to the soil.

Add shredded oak leaves to the compost mix, slugs don't like the tannin they contain.

Encourage birds, frogs, beetles or a hedgehog to your garden, they will all eat slugs and snails. But more importantly reduce the places where the slugs and snails can hide from these predators. [Further information about encouraging hedgehogs into your garden can be found at http://www.britishhedgehogs.org.uk/]

Slug nematodes are naturally occurring predators of the slug and can be used to control them without worrying about pets or children safety. The nemaslug is a native nematode that swims up to a slug, punctures the skin and starts eating it from the inside out. Packs of nematodes are available commercially here. However they are only effective after the soil has warmed up, typically by mid-March, by which time a lot of damage to new, young growth might have already occurred, also the soil has to be kept moist to keep the nematodes active in the soil. An application of nematodes lasts for approximately 6 weeks and will treat about 40 square metres. They have been approved by the Soil Association to be used in organic gardening.

Commercial slug pubs are available - although you can create your own by pouring beer into a small bowl, put a small jar in the middle of the bowl and place a saucer on top of the jar (this will keep animals from drinking the beer and the rain from diluting it). Slugs are attracted to the smell of the beer, they drink it become intoxicated and drown - shame :-).

If you go out at night with a torch, you'll see plenty of slugs, pick them up and drop into a bucket of salt water, or cut them in two with an old pair of scissors or secateurs.

When slugs and snails move over copper, their slime reacts with the metal, creating a mild electric charge, thus deterring them. If you have raised beds you could put copper pipe around the whole bed, but you might still have to use other methods as well due to slugs already being present in the soil, although this will diminish over time. Copper slug tape and copper coated mats (intended to specifically protect strawberry plants) are available online or from the garden centre, cut to length and stick to the top rim of individual plant pots. Alternatively put the tape around short lengths of drainpipe or cut off fizzy drink bottles and put these over beans or pea plants, when they are first planted.

I was tempted to put slugs on the compost heap, to break down any plant matter, but I was reminded that they will lay eggs in the compost, which I'll then put on the borders.

Slugs can have over 25,000 teeth!

An old slug deterrent remedy suggests taking half a pound of tarragon (Artemisia dracunculus) and wormwood (Artemisia absinthium) leaves. Put into a large saucepan, pour over a pint of water and simmer for half an hour. Allow to cool, strain, add a teaspoon of liquid soap, shake and spray.

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