Which homemade slug and snail deterrents really work?
We’ve all heard of the classic slug-repellent home remedies; copper tape, wool pellets and egg shells (the latter leaving me thoroughly confused when I went to play in the garden as a child) will ensure your lettuces remain untouched by the ravenous gastropods. But a recent study by the RHS has shown that these age-old techniques make no difference at all.
In a test of 108 lettuces grown at the John MacLeod Field Research Facility in Wisley, which lasted for six weeks with various different methods of slug deterrent, the study found that the crops protected by barriers of copper tape, horticultural grit, pine bark mulch, wool pellets and broken egg shells were just as likely to be munched on by slugs and snails as those with no protection.
Similar DIY remedies have been used by gardeners to counter slugs and snails since the 1600s, but it is now thought that, while the sharp textures of many of the deterrents may look unappealing to soft-bodied mammals, the thick mucus covering slugs and snails acts as a protective shield, enabling them to slide right over and into your veggie patch.
So what can be done to keep the pesky plant-eaters at bay? Here are a few easy ideas…
A beer trap
The preferred method of Telegraph garden writer Mark Diacono, beer traps or ‘slug pubs’ as he calls them, are an easy and economical way to wean molluscs off your greens.
Simply cut an inch or two off a yoghurt pot or plastic bottle (or hollow out a melon), stick it in the soil around 1cm above the ground, and fill it with a glug or two of cheap beer. The slugs will migrate over to the containers and drown in the beer.
You’ll need to have a few of these scattered around your veg patch, and the containers will need emptying out and topping up once they start to become more of a beer/slug jacuzzi. Other than that, this method is low maintenance, has no environmental impact, and will only cost as much as the beer you are willing to give them (which needn’t be much, I hear slugs haven’t caught onto the craft beer trend yet).
Raised beds and pots
When the RHS conducted their slug experiment, they varied the location of the lettuces, with some growing in pots and raised beds, and others growing at ground level. Results showed that 5.7 per cent of the lettuces at ground level were eaten by the slugs and snails, compared to just 0.2 per cent of the plants grown in pots and raised beds.
This is the method employed by horticulturist and gardener Jack Wallington, who grows his most vulnerable plants like young dahlias to a substantial size in a pot on a garden table, planting them in the ground only when they are too large for the odd nibble to matter.
Employ some amphibious allies
Following the logic of the nursery rhyme ‘There Was an Old Lady Who Swallowed a Fly’, one way to stop slugs and snails eating your plants is to get something to eat the slugs. Frogs are particularly effective, although they do require access to a pond in order to live happily in your garden.
Alternatively, hedgehogs, birds and slow-worms are also fond of a snail snack, so a warm welcome for these animals in the form of bird boxes, log piles and compost will aid you in the battle against slugs and snails.
Go slug picking
Finally, the simplest and most effective way of protecting your patch is to go out in the early evening (especially when the weather is damp) armed with a torch and a bucket of hot, salty water, and individually pick the slugs off plants. The salty water quickly kills them. Of course, you could capture the slugs and release them in a nearby field, but I would always be left wondering ‘what if it was that slug I released by the compost heap?’ the next time I find a gaping hole in my lettuce leaf.
