Trapping slugs and snails is a mainstay of successful organic gardening. Traps are non-toxic. They don’t endanger beneficial insects, wildlife, pets, or children. And you don’t even have to kill your pests. You can safely relocate them.
There are several reliable ways to trap slugs and snails. One is to collect them by hand. Another is to make your own slug and snail pub to trap them with a yeasty, sugary liquid like beer. Another is to use an inexpensive commercial product like the Slug Inn trap. However, may like to learn what it is that entices snails and slugs to your backyard in the first place?
Some particularly diligent gardeners venture out into their gardens at night, flashlight in hand, inspecting each plant, gathering slugs and snails by hand. This method is a lot of work, and it is not the most efficient or effective method of natural slug and snail control. Don’t go out to your slugs and snails. Let them come to you.
The simplest way to trap slugs and snails is to place a piece of plywood or a board over moist, soft, compost-rich ground and leave it overnight. Just lay it on the ground. Don’t tamp it into the dirt. You want slugs and snails to be able to crawl under the lumber. If you don’t have lumber, cardboard, an upturned flower pot, or even large leaves of cabbage or lettuce will do.
Don’t check your trap until the next day. Slugs and snails will gather under the lumber, and all you have to do is to lift the lumber to collect them. With gloves on your hands, use tweezers or a pair of chopsticks to pick up the pests, place them in a sealed bag or small container, and throw them into the trash. You could simply relocate them into the woods, but you need to take them at least 100 meters (300 feet) away from your house. Resist any temptation to smash the snails and slugs by stomping on the board. This would release their eggs into your garden. Be sure to place your trap away from your prized plants, since you are attracting slugs and snails with it.
A favorite method of snail and slug control is trapping them with beer. All you need to do this is a plastic bottle, some tape, and your favorite lager. If you don’t keep alcohol at your house, you can also use a mixture of brewer’s yeast, sugar, and water. Any kind of plastic bottle works, although green plastic blends in better with the landscape and half a pint to a quart (half-liter to a liter) bottles are the optimal size.
Cut the empty, open plastic bottle just below the neck. The top of the bottle will look like a tiny funnel. Place the “funnel” upside down into the lower part of the bottle, and seal the two parts together with tape.
Dig a hole deep enough to contain the bottle with about half an inch (10 mm) extending over the ground. This keeps beneficial insects from falling in. Add enough beer to make the bottle about half full. You don’t want beer all the way up to the bottom of the funnel, because you don’t want snails and slugs to have a way out. Place the bottle in the hole, and leave overnight. You don’t even have to bury the bottle into the ground at all. You could just place it on its side. However, if you don’t bury the bottle you are more likely to capture beneficial insects and you won’t catch as many slugs and snails.
The next morning you should have a collection of inebriated slugs and snails ready to be thrown away. They won’t really drown in the beer. They typically can survive submersion under water for several days. But they will be very happy as you throw the bottle away in the trash, with no mess and no fuss. Repeat the process every day until you don’t catch any more of them.
Alternatively, instead of trying to trap slugs or snails, you can keep them off your plants by using copper mesh and copper tape barriers.