If you want to grow your own food and save money, you have to make sure that you don’t lose too many of your crops to pests and diseases. Slugs and snails are some of the most demoralising pests in a kitchen garden, as any gardener who’s had row after row of seedlings mown down by these slimy creatures knows.
So, how to get rid of slugs and snails in the garden or allotment? It isn’t easy, and any successful campaign needs to have more than one approach as single-pronged attacks are rarely effective. Combine any or all of the following to get the upper hand over your local mollusc population:
- A kill on sight policy
- Slug pellets
- Irritating surfaces
- Bio-control with nematodes
- Encouraging predators
Whatever you decide to do, don’t start throwing salt around your growing space, as it’s really bad for the soil and your plants.
A kill on sight approach
Sorry if you’re feeling a bit squeamish, but killing slugs and snails as and when you see them is a good way to get rid of them. Just squish them and kill them instantly, and leave them for the birds to eat. They especially like to come out in the evenings during damp weather, so you could even do the occasional slug and snail hunt at dusk, armed with waterproofs and a torch.
There are some people who relocate slugs and snails, say, to local wildlife areas, instead of killing them. Each to their own.
You have a choice between inorganic and organic slug pellets. The inorganic ones are potentially toxic to kids, pets, the environment generally and anything that might eat the dead slugs or snails (birds, mammals etc) – probably best avoid using them if you can as they are a bit too poisonous for their own good. The organic slug pellets mostly work by doing the slugs and snails in with minerals such as ferrous phosphate – they are less effective generally, but they are far, far less harmful to other wildlife/pets/kids/plants. The organic pellets also seem to need more regular reapplication.
Slugs and snails ride along on a wave of mucus – bletch – and anything that breaks up this mucus or prickles against their slimy underbellies tends to make them move away. Make rings of simple irritating surfaces around your prized plants with grit, coarse horticultural sand, ceramic chips, crushed eggshells, coffee grounds, and anything else non-toxic you can lay your hands on.
You can also create protective collars out of large plastic drinks bottles, and put them around your seedlings etc. Cut off the top and bottom of the bottle, then cut a zigzag pattern through the middle section to make two collars with jagged edges – and mind your fingers. Probably not suitable if you have toddlers or pets.
Bio-control with nematodes
This stuff is frankly genius, and it’s organic too – although be warned, it only kills the slugs and not the snails. For a few quid, less than £10, you can buy packets of live microscopic parasitic nematodes. One commonly known brand is Nemasys. You open the carton into a clean watering can, add water and spread the nematodes out around your allotment before adding some more clean water on top. If you miss a bit, don’t worry, they will spread out on their own and fill in the gaps.
The invisible nematodes then get inside the slugs and kill them. It’s very effective, and it lasts for about 6 weeks – best to add some at the start of the growing season, usually April-ish, to get the numbers of the slug breeding population right down. Most slugs live invisibly under the surface of the soil and this is probably the single most effective way to kill them.
What are the cons of using nematodes to kill slugs? Well, it is relatively expensive. You also get quite a lot in a pack, perhaps more than you’d need for a small garden, and the pack isn’t resealable so it has to be used all in one go. However, you could go halves on one with a neighbour or fellow allotment user. If you have a major slug problem you are also likely to need repeat applications a few weeks later.
Traps for slugs and snails
The most well known slug and snail trap has to be the beer trap. By which I don’t mean the slimy little creeps will drive you do drink, oh no, quite the opposite in fact. You can buy commercial traps, or you can make your own. Sink a small container into the ground, pour in some value-range supermarket beer, and walk away. In the evening, the slugs will be attracted by the smell, reach out to take a sip, get drunk, fall in and drown. This is pretty cheap to set up, although you might baulk at buying your garden enemies a beer. You will, however, need to set up quite a few beer traps, they can get pretty stinky, and they are GRIM when the time comes to empty them.
Beer traps aren’t the only traps, though. Set down a large-ish fruit peel on the ground in the evening, such as a melon or grapefruit, then turn it over first thing in the morning. Chances are there will be some slugs or snails sheltering inside the dome. You can also check out their other favourite hiding places, such as under pots or below the lip of a planter.
Slugs and snails have quite a few natural predators, including many birds, frogs and hedgehogs. If you have a large enough garden, and the right conditions, consider setting up boxes and other places for them to make their homes.
Do you have any other ways to get rid of slugs and snails? Please share them if you do.