Great ways to deal with slugs

There are many ways to deal with slugs, but the first thing to note is that not all slugs eat living plants, writes Bob Sherman. 

When you lift the lid of the compost bin lid and find a long, sleek monster, grey and spotted like a leopard, you're meeting a slug that feeds on decaying matter, as many do.

Some slugs even eat other slugs.

The ones to worry about are black slugs known as keeled slugs and the grey and brown field slugs that you find all over the garden at night, especially after or during rain.

There are no food plants I can think of that are immune to slugs and snails.

What you might notice, however, is that in a row of, say, broad beans, one plant will have been visited again and again and eaten down while others nearby are barely touched.

Plants are not defenceless. They are responding to the chemical signals given off by the attacked plant and releasing toxins to keep the slugs and snails away.

So when it comes to sowing and planting, assume you'll have some casualties and plant more than you need.

As for actually killing slugs and snails, here are some organic ways to do it.

Encourage slug eaters

Some creatures love the flavour of slugs and snails. Smashed snail shells indicate that thrushes are around. Hedgehogs search out slugs, especially in autumn.

Ground beetles will find them in places you can’t reach or see, and then eat them. So encourage wildlife by leaving a wild area in your garden if you have room.

Protect young plants

Recycle your 1 litre pop bottles by discarding the screw top, cutting off the base and pushing the sawn-off bottle into the soil to protect small seedlings.

The tile trap

Place a tile or slate on the surface of the soil with a few outer lettuce leaves or other peelings under it. This will attract snails and slugs, which can then be killed or relocated to distant wild countryside.

Slug pubs

Slug pubs containing beer or lemonade will attract slugs, which then drown. You can buy slug pubs or make one from the bottom of a plastic bottle. Unfortunately these devices also drown beetles and other beneficial creatures. Raising the lip above the soil surface by 1cm reduces this risk.

Parasites

I am a firm fan of nematodes as a solution. These microscopic parasitic worms are watered on to warm soil (6 degrees) in wet weather to hunt down the slugs under the soil. You have to send off for these but they are fairly readily available in catalogues.

Pellets

Also effective are the pellets made from ferric phosphate, a natural substance that is non-toxic to other organisms but which kills slugs and snails. You can get these in almost all garden centres or by mail order.

The Organic Gardening Catalogue lists more than 15 different ways to deal with them safely including a shot of caffeine.

Bob Sherman is Chief Horticultural Officer at Garden Organic