Got a slug problem?

Gardeners often cite slugs as the most annoying garden pest! They love to gobble up fresh shoots and they can decimate your seedlings over night. Here we discuss slugs, methods of control and their role in the ecosystem – it is not all bad!

The role of slugs

Most slugs are generalists, feeding on a broad range of organic material, including leaves from living plants, lichens, mushrooms and carrion (dead and decaying flesh of animals). Some slugs are also carnivorous and will, on occasion, even eat the dead of their own kind. Slugs can feed on a wide variety of cultivated plants, but they particularly love the green shoots of cabbages, lettuces and the early leaves of squash and courgettes. Some slugs are predators and eat other slugs and snails so they are not all bad! The Leopard Slug is a predator of other slugs so actually a helping hand for you to have around.

There are a wide variety of slug species

Various species of British land slugs, including (from the top) the larger drawings: Arion ater, Kerry slug, Limax maximus and Limax flavus.

Adams, Lionel Ernest (1854–1945) – Adams, L.E. 1896. The collector’s manual of British land and freshwater shells. Second Edition. Taylor, Leeds. File is from

BBC’s Countryfile on have produced an excellent guide on identifying UK slug species.

Controlling slugs

Natural predators:
Slugs are preyed upon by virtually every major vertebrate group so encouraging a range of wildlife to your plot can help the slug population stay under control. Birds that prey upon slugs include common blackbirds and starlings. Mammals that eat slugs include foxes, badgers and hedgehog

Several species of nematode worms are known to parasitise slugs. Parasitic nematodes (Phasmarhabditis hermaphrodita) are a commercially available biological control method that are effective against a wide range of common slug species. The nematodes are applied in water and actively seek out slugs in the soil and infect them, leading to the death of the slug. This control method is suitable for use in organic growing systems

Transplant out robust plants
One way to try and ensure your plants survive slug attacks is to allow your plants to be a reasonable size before planting out. This way they are better able to withstand a little damage.

Remove slugs physically
Not for the faint-hearted, but going out at night and dispatching them is very effective if you are happy to do this

Reduce habitat
If you keep the areas around your plot including storage areas, paths and grass verges tidy there are less places for slugs to breed.

Create a physical barrier
It is said that slugs don’t like crawling over sharp or water-absorbing structures like egg shells. Wool-based pellets are too dry for slugs to crawl over. Beer traps attract slugs and work well, but these need regular maintanence as they all wash away quickly in the rain. Copper tape is said to be a deterent – expensive though!

Chemical control
Inorganic methods (like the blue metaldehyde pellets) work well, but can affect other wildlife. There have been recent moves to control the sale of this product, but unfortunately this has been overturned. We would recommend avoiding using metaldehyde pellets. ‘Organic’ slug pellets are made from Ferris phosphate. These do not pose the same risk to wildlife and break down in the ground to iron and phosphate.

The Gardener’s friend: The Leopard Slug:

By Michal Maňas – Own work, CC BY 2.5,

Identification features

  • Up to 16cm long when fully grown
  • Brown or grey, with brown or black spots/blotches
  • Front of body has marbled pattern of spots (never stripes)
  • Back of body has up to three dark stripes on each side –dark stripes may be broken up into a line of dots
  • Underneath (sole) is white

The slug population can be very dependent on cold spells (or the lack of them) during the winter months. The slug population this year may be quite high due to this. Whatever method you chose you will probably have to accept that the battle with slugs is part of the life of gardener.May your crops survive and may Leopard slugs support our fight.