Controlling slugs and snails

They take on many different forms but it is the "keeled" slug variety (of which there are many) that does much of the damage-especially to potatoes.

The larger multi-coloured slugs that some gardens tend to be invaded by are less of a threat. They tend to live and prefer wild hedgerows and are not normally very destructive in the garden environment.

It is estimated there are around thirty different species of slug in Britain. Slugs and snails move around by using a "muscular foot" which secretes mucus along which they glide. This mucus of course then dries to form the distinctive slimy trial that gives their presence away to frustrated gardeners.

It is this time of year when these slimy molluscs start to rampage through our seedlings annually wit monotonous regularity. Thankfully there are some measures we gardeners can do to minimise damage without resorting to those nasty blue pellets.

Dealing with the problem

There are many tried and tested ways of dealing with slugs and snails that work for some people more than others. It would be impossible to list them all here in this article. No two patches of soil or climate conditions are ever quite the same so control methods are also variable in their success rates.

Perhaps the most infamous natural slug control for generations has been the beer trap. Here a small container is filled with beer and sunk in the ground. Of course the idea is the slugs fall in and drown in a happy and intoxicated state! It has to be said you will need a lot of traps to cover a large area. Perhaps buying shares in your local brewery before you start is also a good plan. The success rate, is patchy and in my experience cannot be relied upon entirely as a form of control-especially if the slugs in your area are teetotal.

There is a serious note to this method. Please remember if you try this to leave the rim of the container considerably raised above the soil level by between 2-4 cms to prevent allies and predators such as the black ground beetle from falling in. This would be counter-productive as this beetle feeds on slugs and should be encouraged in the soil. A less alcoholic variant of this theme is to place half a melon on the soil filled with water.

Another traditional tip is to use crushed eggshells spread around the stem in a circle, though I'm not sure how practical this is on a large scale. I have found this fiddly and laborious, with the problem that vast quantities required to cover any reasonably sized area. This is one to avoid in my view.

In a similar vein putting used coffee grounds in a ring around plants is reputed to be effective as a barrier they won't cross. This is not one I have tried myself.

Still with coffee - the humble watering can plays it's part too. Try diluting three tablespoons of instant coffee and pouring on the affected area. Or adding 1tbsp of crushed garlic in the can before watering.

Other suggestions are to smear petroleum jelly around the rims of pots to stop slugs entering and devouring your young seedlings.

Other tips include putting small piles of bran around the garden near to vulnerable plants. I'm assured this is very effective and reputed to be safe for birds too.

There is a school of thought suggesting slugs are habitual creatures and like to follow their existing trails. Regular hoeing and destroying these trails may confuse them and deter them to some degree.

Another classic method - that is a little more fun - is to go out at night on a slug and snail hunt with a torch and gather them in a bucket. This is a great adventure with non-squeamish children and is particularly effective on a damp humid night. You will be surprised just how many snails there are on the pavement after a shower of rain, especially near stone walls. It is the wet weather coupled with mild temperatures that brings these little beasties out of they're hiding places to feed.

Nematodes

Nematodes are available to buy via mail order or sometimes the garden centre and are useful for clearing areas of land of around 100 square metres per pack. Nematodes are biological safe slug control at it's best. Each pack of nematodes contains millions of these tiny naturally occuring microscopic parasitic worms that are found in the soil.

They work by searching for the slug, stopping it feeding and usually killing it within several days. This is a completely natural slug control that can be used near pets, children and wildlife. One application lasts approximately six weeks and so the canny gardener uses the packs at strategic times, ie: seed sowing to keep the cost down. Potato tubers are of course also vulnerable, so using this control 6-8 weeks prior to harvesting is an option some gardeners employ.

Nematodes are not recommended for heavy clay soils as they are less effective and they need a temperature of 5-20C to work most effectively.

The easiest way to apply nematodes to your soil is to use a watering can in early evening. First mix the pack with water in a bucket stirring vigorously and then transfer the solution to a watering can with a hose attached and apply to moist soil. Any solution that lands on foliage should be washed off with water.

The one downside that cannot be overlooked is the cost. It can work out quite expensive as each pack costs around £30. It can be seen therefore that this control is ideal for relatively small areas only. While the cost of slug damage has to be taken into account if left unchecked, a decision has to be made, after judging the financial pro's and cons. If you are one of the lucky ones where finance or heavy clay soil is not a consideration then this could definitely be for you.

Switch on to Copper

I've saved my personal favourite till last. Copper gives off a tiny positive electric charge that molluscs will normally not cross. Copper comes in my guises. For a DIY version use a copper strand of wire attached to the rim or base of pots in greenhouses and on staging etc. Wire can be obtained easily and cheaply from your local DIY retailer and is easy enough to fix to pots of all shapes and sizes. Also available is copper tape, copper bands and mats which are variants of the above.

Self adhesive copper tape works in the same way and can be placed around vulnerable pots to prevent slugs and snails reaching the seedlings or young plants. If snails are a particular problem try serrated copper tape aimed specifically at them which is more likely to be successful.

Finally don't forget we humans have friends in high places that will go about their daily business hovering slugs and snails up for us if we give them the chance. I'm taking about ducks, poultry, frogs, hedgehogs, birds and badgers who are just a few of the outdoor creatures who will devour them. Encouraging these creatures will go a long way to controlling slugs without costing very much money at all. Hedgehogs can be encouraged by making a small den or hiding place with piles of logs and twigs. Meanwhile building a water feature in the vicinity of your vegetable area will pay dividends over many years attracting allies such as frogs. A lot of this happens in the dead of night when we are obliviously unaware. The switched on gardener will tip the odds in his or her favour by good husbandry such as exposing the soil to winter frosts and foraging birds desperate for a winter snack. Turn back any weed suppressant or stones or wood laid across the soil to reveal a mass of slugs in summer of all different shapes and sizes. Remember that molluscs like to keep in the moist shade during hot weather - so we can use this to our advantage.

The above is not an exhaustive list, but it does show that we gardeners and growers now have a lot of firepower on our side without resorting to the ubiquitous and increasingly unpopular blue pellets. There is no need to put down this now dated chemical form of control. Try some of the above and find out what works for you. It may be a combination of some them all or one in particular.

However you approach slug control there is something out there that will work for you. If any reader has any particular success story to report why not email me at: leeseniorgardening@yahoo.co.uk or post a message on the forum.