Organic Slug Control

The garden slug is one of the worst pests out there. Here’s how you can control it organically.

We’ve had a bumper year for slugs. That’s because the winter was mild and there were few frosts to kill them off, followed by a warm, wet spring. Bad news. A lot of gardeners have lost a lot of plants to slugs.

organic slug control

Here’s the essential  guide to keeping your plants safe from slugs. It’s worth deploying a mix of methods: just one won’t protect you in a heavy slug year.

garden slug

1. Garlic barrier

These days, we cover all our plants in finely-chopped garlic. Simply put as many garlic cloves as you can lay your hands on, whack them in a food processor with the blade on, and whizz on high speed until the garlic is chopped into little pieces. You do not need to peel the cloves. Then apply them around the base of each vulnerable plant. Slugs hate the scent of garlic and won’t go near the plant, and if they do, they hate the taste of garlic too.

2. Garlic spray

For non-edibles that slugs really, really love, like hosts, boil up a very stinky garlic spray from your chopped garlic and spray it all over the leaves of the plant. Crush the cloves from two garlic bulbs into a saucepan of boiling water, add chilli powder, and leave to simmer (with the lid on and the windows open) for half an hour. Decant into a spray bottle, and spray all over your plants.

protect plants from slugs using vaseline

3. Vaseline barrier

This is a great and very effective way of keeping slugs off tender and tasty young plants. Our pumpkins wouldn’t survive if we didn’t have these barriers. Cut old plastic milk bottles into thirds, or cut the bottom off a plastic pot, and smear generous quantities of Vaseline all the way around on each one. When placing this around the plant, take extra care to make sure it is anchored in the soil so that the slugs can’t sneak in underneath and eat the plant.

4. Baked eggshells

You can mix these in with your garlic barrier to create a sharp and painful surface that the slugs will not want to cross. Bake them in the oven for 20 mins, and then break up into small pieces.

5. Wool pellets

I sprinkle these around plants, and they form a barrier with an uncomfortable surface that the slugs prefer not to slide across. But they have to be reasonably widely applied, otherwise the slugs decide it’s still worth the uncomfortable trip, so make sure you use garlic too.

6. Copper tape

Great for pots and containers, as the slugs hate crossing the copper as it emits an electrical charge whenever they try. You could also make some more permanent Vaseline barriers which have both copper tape and Vaseline on them, replenishing the Vaseline each time you re-use it (don’t smear the Vaseline over the copper tape, though!).

7. Picking them up

Slugs are fine and helpful on your compost heap. So when it’s raining and dark, go into your garden and hunt around your vulnerable plants with a torch, and put the offending slugs in a bucket. Of course, the problem is that they will lay eggs in the compost, so if you’d rather cut down numbers, then exterminate the slugs, either by doing something unpleasant to them involving the sole of your boot or a pair of scissors (sorry, squeamish people), put them on a bird table that they can’t crawl off, or if you have chickens, feed them to your chooks.

8. Nematodes

In spring, water in these microscopic parasites into the soil. They will kill your slugs and keep the numbers down for the rest of the year, but the dead slugs will be perfectly safe for your birds.