Avoiding shell shock: Diarmuid Gavin on how to protect your plants from snails
There are many natural ways to fend off the gardener's greatest enemy - the snail
Published 10/07/2016 | 02:30
For many gardeners, slugs and snails are the primary enemy - the pests whose destructive power leaves us feeling angry and frustrated.
Our current weather creates perfect conditions for slugs and snails, as they love a damp climate and when they're hungry, they dine on the most tender and lush foliage they can find. They often do this under cover of dark when few gardeners are keeping watch, and we typically react with fury when we discover shredded foliage and flowers the following morning. So, our tolerance for these creatures tends to be low.
As gardeners, we need to know the best way of controlling these garden invaders. First of all, it pays to know which plants they prefer. Hostas are the caviar of the slug and snail world, and in my garden the pests have also stripped bare newly planted heleniums and omphalodes. But they have left alone peonies, thalictrum and the day lilies. They tend not to like the tough foliage of bergenias, acanthus, ferns, grasses, Japanese anemones and echiums, whereas they feast on dahlias and delphiniums - with strawberries and lettuce for dessert!
Sometimes, it's a matter of watching the gourmet tastes of your local snails and planting accordingly.
What other steps can be taken to alleviate the damage?
Firstly, keep the garden as dry as possible in the evening by watering in the morning. This means the surface soil will be dry by evening. Studies show this can reduce slug damage by 80pc.
If you have access to seaweed, mulch it around the base of your plants making sure to keep it away from plant stems so it's not in direct contact. Not only is it good soil conditioner, seaweed is also a natural repellent for slugs because of its high salt content. Pile it on three to four inches thick - when it dries it will shrink to just an inch or so. In hot weather, seaweed will dry and become very rough which also deters the slugs.
Slug pellets will kill snails and slugs but they can be dangerous if you have pets, and they aren't good for the snail's natural predators such as birds and hedgehogs either. There are organic slug pellets which are less environmentally harmful, but you are still killing the snails.
An alternative approach is to encourage the natural predators so that snails are eaten as part of the food chain. A wildlife-friendly garden will have birds, hedgehogs and frogs, which help to keep populations in balance.
You can also make an obstacle course for slugs and snails to prevent them from getting near to your plants. This could take the form of a copper band, either around flower pots or even as a barricade in the soil. Touching copper gives them an unpleasant electrical shock.
Cut 3cm-strips of thin copper and wrap around the lower part of flower pots. Or you could set the strips in the soil at the edge, creating a mini fence which the slugs will be very reluctant to climb. Copper barriers also work well around wooden barrels which have been used as planters.
Garlic-based slug repellents are gaining a lot of fans. The slug-control product ECOguard uses garlic as the active ingredient. You can make your own non-toxic homemade garlic slug-control spray by combining crushed garlic cloves, garlic powder and water in a spray bottle and misting plants which are at risk with the solution. Slugs will consume the garlic and die shortly afterwards.
Gritty or spikey substances such as broken egg shells or sharp pebble around the base of the plant can make it difficult terrain.
Other remedies include luring them using beer traps so they fall in and drown.
You just need a small amount of beer in a shallow wide jar buried up to its neck in the soil. Prop the lid up with a small stick so rain won't dilute the beer and leave space for slugs to enter the trap. They'll soon be lured by the intoxicating scent.
Or if you're a bit of an insomniac like me, you could patrol at night - when these garden pests are most active - and remove them from leaves, pots and pathways and re-home them somewhere else.
Feeling sluggish? try a coffee
Scientists have discovered that coffee is remarkably effective at repelling slugs and snails. Recent studies have indicated that the garden pests hate caffeine. Environmentally-friendly repellents based on caffeine may soon be produced, but for now sprinkling coffee around the edge of flower beds might be enough to put them off. Preliminary trials showed that caffeine does not damage many plants, even if placed directly on the leaves. However, it did cause ferns and lettuce to develop some yellowing on their leaves. You could collect waste coffee grounds and scatter them on top of the soil. Moderate use of this method is advised as its still uncertain how detrimental this is for soil structure.