Every Spring season, it’s the same old story. You’re strolling through the garden, soaking in that frenzied feeling of nature waking up. Ka-POW, disaster strikes! Everywhere, slugs and snails chowing down on young sprouts, wispy stems standing as tiny totems to spirits of the past… Gone are your favorite flowers and vegetables! To make sure your sprightly Spring mood doesn’t swing up and down this much, follow these tips on how to control them naturally.
There are two main types of slugs in our gardens. Common garden slugs (Arion hortensis) and large black or red slugs (Arion ater). Regarding snails, you’ll probably notice the garden snail (Helix aspersa) and, though less common, the garden banded snail (Cepaea hortensis) or the grove snail (Cepaea nemoralis).
Let’s look at the patterns in the life slugs and snails.
Symptoms of slug and snail attacks are generally stems cut about an inch high (2-3 cm), with leaves missing entirely. If you notice seedlings falling over or turning yellow, it isn’t these guys: it’s “damping off” due to fungus.
The better you “know your enemy”, the easier it is to deal with it. The first step is thus to create a barrier between plant and ground: pick up fallen fruits and don’t let withered leaves trail back down to the ground. These are like bridges for the slimy little buggers. That way, the only way to climb the plant is the stem or trunk. Protecting that single point of entry is easier.
These will keep Gastropoda numbers down. Among the most voracious helpers, you’ll find hedgehogs, toads, and also nematodes which are microscopic worms that parasite and attack slugs. They’re sold in garden stores and look like powder. All that’s needed is to mix them into water and spray it all over the ground.
Certain plants naturally repel slugs: thyme, chives, fennel, comfrey, garlic, centaury, etc.
Others such as chamomile tend to attract slugs to them. You can use them as decoys to draw them away from your prized crops.
Further protection is available through the use of natural barriers that discourage slugs and snails from devouring young sprouts. For instance, chimney ashes (if you have a fireplace), used coffee grounds, coarse sand or grit, and even crushed egg shells. The main drawback of these barrier techniques is that they’re washed out by rain. Therefore, they need to be replaced every time it rains.
Interestingly, snails and slugs absolutely hate slithering across copper, believe it or not! To that end, twist electric wire (after removing the plastic sheath) into a barrier you can wrap around stems or plants to create a natural anti-slug fence.
Another possibility to deal with slugs and snails is to trap them. Two options here:
Each of the methods described above works in a different way, and none of them suits every situation. This table sets them side by side so you can pick the one that matches your plants and your patience.
| Method | How it works | How to use it | Point to watch |
|---|---|---|---|
| Nematodes | Microscopic worms that parasite and attack slugs | Mix the powder into water and spray it over the ground | Bought from garden stores |
| Hedgehogs and toads | Voracious predators that keep gastropod numbers down | Welcome them into the garden | A long-term balance rather than an instant fix |
| Repellent plants | Thyme, chives, fennel, comfrey, garlic and centaury are naturally shunned | Grow them among or beside vulnerable crops | Repels rather than removes the slugs |
| Decoy plants | Chamomile attracts slugs to itself | Plant it away from prized crops to draw them off | Gathers slugs, so keep it at a distance |
| Dry barriers | Ashes, used coffee grounds, coarse sand or grit and crushed egg shells stop them crossing | Spread a ring around young sprouts | Washed out by rain and must be replaced each time |
| Copper wire | Slugs and snails hate slithering across copper | Twist stripped electric wire around stems or plants | Remove the plastic sheath first |
| Cocoa hull or flax mulch | The mulch itself acts as a barrier | Sprinkle a few handfuls after rain | Needs topping up to keep the effect going |
| Passive shelter trap | A stone, board or upturned pot lures them to hide by day | Turn it over, collect the animals and move them elsewhere | Needs checking every day |
| Beer trap | Yeast attracts slugs, which swim until they drown | Sink a container near the crop | Use containers that keep other animals out |
Combining a barrier with a decoy or a trap usually works better than relying on any single method.
The goal of this article isn’t to learn how to eradicate and kill off all slugs and snails from your garden. They’re on Earth for a reason, and, in their own way, are very helpful in a garden. They work to convert plant waste into fresh nutrients that your plants can use to grow. Your garden, in the long run, will be better off with snails and slugs than without!
