How to Get Rid of Slugs and Snails in the Garden

 Remove Hiding Places for Slugs and Snails

The first step towards a more manageable slug population is to remove hiding places from within and around your main growing areas. 

• Cut down long grass right around vegetable gardens. Through regular mowing, you’re removing these opportunities for slugs to lay low.
• Remove debris lying about. Upturned pots, bits of wood, old sacks – they are all potential hiding places for our slippery slimesters.
• Work within beds to remove any dead or dying leaves as well as, of course, any weeds. Removing all this excess vegetation to the compost heap keeps things more open in our growing areas, improving airflow and discouraging the damp, shaded conditions slugs love.

Trap and Remove Slugs and Snails

1. Create the perfect slug and snail trap by laying boards, cabbage leaves, or pieces of cardboard on the bare soil around your plantings. Start by watering the ground if it’s dry, then place a plank of wood or similar over the surface. Check back the next morning, and you’re very likely to find slugs lurking beneath. Pick them off and return the plank to collect the next batch.
2. Citrus halves, like grapefruit skins, are highly effective slug collectors because they create a cool, shady recess for our slugs to hang out in. Again, lay down shells at strategic locations—close to susceptible crops like salad greens or tender seedlings. For something longer-lasting, you can use half a coconut shell at each corner of your raised bed (after you’ve enjoyed the coconut flesh, of course), which they like to crawl into.
3. Then, there are beer traps. Everyone knows about luring slugs to a drunken death by placing shallow dishes of beer around the garden. They can’t resist the stuff! Note that any yeasty, sweet liquid will attract them, so keep the beer for yourself and make a gooey brew that the slugs will find delicious by mixing equal parts flour and water with a heaping spoonful of molasses, a sprinkling of cornmeal, and a teaspoon of yeast. Put this goop in shallow containers around the yard, and it will have much the same effect as beer without having to ask for ID.

Go On a Slug Hunt!

If you really want to make an impact, go out on the hunt for slugs when they’re most likely to be out and gorging on your plants: at night, particularly in warm, damp weather. You’ll need a bucket and a flashlight for this. Head out soon after dusk to begin your hunt. Relocate slugs to a less susceptible area, add them to your compost heap, or, to be sure, take them out to a nearby wooded area or something similar. Go on further slug hunts over the coming nights, and you’ll pick up the stragglers and should make an appreciable dent in the slug population.

If you want to dispatch of your slugs, you have numerous gruesome ways to do this—from drowning them in a bucket of water to squashing them. It depends on how squeamish you are! A more humane approach would be to drop the slugs into a container, cover and place in freezer for three hours; when frozen stiff, dump them on your compost pile. Or, simply relocate them!

Ready to think like a slug? Ben shows us how to make many of the control methods!

Slug Pellet Alternatives

We’ve moved on from using commercial slug pellets due to their impact on other animals and the environment; many are laden with chemicals that do a good job of killing slugs but may also harm animals higher up the food chain. In our enlightened times, we should look at alternatives.

One option is to apply microscopic nematodes onto slug-affected ground. The nematodes are first suspended in water and then watered over soil that has warmed up enough following the winter months. The nematodes find their way into the slugs, where they infect them with a deadly bacteria. It sounds grim, but these nematodes come with zero collateral damage, making them a very safe form of slug control.

Physical Barriers

Several studies have shown that a barrier of diatomaceous earth (DE) can help. This is a naturally occurring, silica-based substance that can be crumbled into a fine powder. Slugs really don’t like crossing the moisture-sapping powder. Create a thick barrier of DE that’s at least 3 inches in width. Just make sure you buy “food grade” DE. This works best in dry weather; it will need to be replaced when it gets wet. 

Studies have also shown that barriers made of copper, like copper tape, bands, screening, or foil, can repel slugs. When slugs or snails interact with copper, it gives them a sensation akin to an electric shock, causing them to avoid the material. This works best on a small scale, as surrounding an entire patch with enough copper material can quickly get unwieldy. Wrapping pots or planters in a band of copper that’s at least 1 inch wide is the most efficient way.

What Does NOT Work

Many solutions that have been tested are not very effective, including bark mulch, wood ash, coffee grounds, coarse sand, pine needles, eggshells (yes, eggshells!), sharp grit, and wool pellets. Every study has found these to be useless. 

More Slug Control Tips

• Some plants have been shown to thrive despite being around slugs and snails. If you tend to see these pests and are having trouble getting rid of them, try planting astilbe, phlox, or mint to reduce damage.
• Water plants in the morning if possible—this will give the soil surface time to dry out a bit before nightfall when the slugs come out.
• Vulnerable crops, such as leafy greens and salads, can be started off in pots or plug trays away from the growing areas. By the time they are planted, the plants will be that much bigger, more robust, and better positioned to withstand attacks.
• You can protect recent transplants with cloches or any barrier that physically keeps slugs out, such as bottomless plastic bottles popped over individual plants.
• If you grow potatoes, dig them up as soon as they are ready because slugs love these tubers. Some varieties are also more tolerant of slugs than others.
• Slugs and snails have many natural predators. If you have chickens or ducks, they will help by eating these pests and their eggs. Amphibians, such as frogs and toads, love to feast on slugs.
• Firefly larvae are also natural predators, so find out how to attract fireflies to your garden.  
• Garter snakes, turtles, and salamanders consider slugs delectable, so don’t freak out and run for the hoe next time you see a snake in your garden. Remember, the enemy of your enemy is your friend.
• Companion planting is an effective way to deter pests. In order to keep slugs and snails away from more valuable plants, place plants that they love near your more valuable plants as a trap, and then destroy the infested plants. Good traps for slugs include chervil, marigold, and thyme.