The copse snail is a real nuisance in the garden—here’s how to get rid of it!
When copse snails appear in your garden, it’s time to act. Päivi Korpivaara, an expert in controlling copse snails, shares methods to successfully eliminate this mollusk.
Enclose your garden
Prevent copse snails from entering your garden. If new snails are pouring in from neighbors or park areas, controlling them in your own garden won’t help. Make use of the repellents presented in this article, as well as pine bark, sand, and gravel mulches, and beds of flowers that snails dislike.
Build a frog pond
Frogs, as well as beetles and other predatory insects, are among the most effective enemies of the copse snail. Voles, mice, and shrews eat snails and their eggs when other food is scarce. Hedgehogs, raccoon dogs, and dogs, on the other hand, can catch lungworm from snails.
Attract birds
Thrushes and starlings are also good natural enemies of snails. They can’t keep large infestations at bay, but it’s still worth attracting them to your garden with winter feeding and birdbaths. Corvids mainly eat copse snails that have been squashed.
Repel with birch products
A doctoral thesis proves that birch bark tar and distillate effectively repel snails and slugs. The Birch Bark Tar fragranced paint by the Finnish company EcoKoivu is a ready-made mixture of birch bark tar and petrolatum. Applied a few times during the summer, it effectively keeps snails away from the vegetable garden. Birch distillate kills weeds, but also snails and aphids. However, it is not harmful to the snail’s natural enemies—beetles. Spray the distillate on the copse snail’s favorite spots, especially under, around, and inside your garden compost. The substance keeps snails and rodents away and speeds up decomposition. Snails do not thrive in a warm composter!
Weed and watch
Copse snails love to feast on dandelions and thrive under the protection of the plant’s basal rosettes. You can best remove dandelions with a pitchfork when the soil is moist. The basal rosettes of plants like horseradish and columbine similarly provide suitable shady hiding places for copse snails. Therefore, it’s worth regularly checking the undersides of all plants with basal rosettes!
Take advantage of plants that snails hate
Snails don’t like these annual flowers: impatiens, nasturtium, pelargoniums, verbena, cornflower, and fuchsia. They also leave these perennials uneaten: columbine, goldenrod, geranium, moss phlox, forget-me-not, peony, ferns, foxglove, bleeding heart, dotted loosestrife, and great mullein.
Grow a buffer strip
Thymes, catnip, lavender, yarrow, wormwoods, and other strongly flavored plants don’t appeal to snails. You can grow these for protection around your vegetable garden, for example.
Collect copse snails early and often
Start collecting snails in April–May in the evenings when it’s damp. This is when snails are looking for mating partners and food. Use a bucket with a lid or a handled fabric softener bottle with a cap. Each snail that you collect in the spring prevents a hundred new snails later. Even empty shells are worth collecting so that live snails can’t gnaw calcium from them.
Kill mercifully
Large numbers of snails can be dealt with using hot water. Lukewarm water won’t do. You can also use salted, soapy, or vinegar water, or vinegar as is.
Mulch underneath
The bases of bushes and trees attract copse snails. To avoid this, mulch under plants and hedges with gravel, sand, cones, or clean pine bark mulch, which is too acidic for snails. You can also use tomato leaves, yarrow, or tansy as mulch.
Pack down snow
Snails take shelter in ground holes, about five centimeters deep in soil or litter. They can’t survive nights with subzero temperatures if the ground is bare. If the temperature drops to -18 degrees Celsius, their eggs will die and the population will collapse. You can pack down or remove snow from the spot where the snails overwinter, which can be the same year after year.
A copper barrier
Copper is an effective mollusk barrier, as long as it’s not coated with lacquer. Stores sell a product called slug tape, which is a wide copper tape that can be wrapped around flower pots and boxes to act as a barrier. Remember to keep the tape clean!
Get ducks and geese
These birds are better snail controllers than chickens and are particularly suitable for the countryside—especially if there’s a pond nearby. Geese are also effective at getting rid of dandelions.
Use iron phosphate
Iron phosphate products approved for organic production eliminate adult snails by disrupting their digestive systems. Sprinkle phosphate pellets in the snails’ favorite spots. Start as soon as they wake from winter hibernation. The pellets remain intact for a week or two and work even after rain. Spread iron phosphate under outdoor stairs and terraces as well as these provide comfortable conditions for snails.
Use hair barriers
If you have a cat or a dog, collect their hair and make big balls of hair. Animal hair around plants prevents snail movement.
Limit hiding places
Snails thrive in moist places with abundant vegetation. Typical hiding places are ditch edges, wastelands, and long grass. All measures that reduce hiding places and dry the environment prevent snails from multiplying.
Dispose of dead snails
- bury large quantities 10–20 centimeters deep
- burn
- add to a hot composter or take to your local waste company’s biowaste bin
- take to the mixed waste bin in a plastic bag
Forget these methods
- beer, wine, cola, and coffee traps
- commercial slug traps
- insecticides and biological nematode control
- sprinkling salt, because plants suffer from it
Stay up-to-date
Eliminating copse snails from your garden is easier when you know the mollusk and the control methods that work on it. Useful reading:
- Päivi Korpivaara, Piha puhtaaksi lehtokotiloista (Docendo 2016)
- Koivunen, Malinen et al., Suomen kotilot ja etanat: opas maanilviäisten maailmaan (Bookwell 2014)
Copse snail in a nutshell
- Appearance varies. Usually, an adult copse snail has a dark brown shell with light spots, and it may have a dark stripe. The snail can also be identified by the trail of slime it leaves.
- The copse snail has a keen sense of smell. The eyes are located on long tentacles. Diet: The copse snail scrapes leaf surfaces and eats holes in them. It also eats dead animals, even its own species, and excrement.
- Each copse snail has both female and male reproductive organs, but the snail usually mates with another member of the species, after which both of them can lay eggs. The copse snail can store sperm inside itself and lay eggs when the weather is favorable.
- The shell lip of a sexually mature copse snail is white. The snail lays 20–80 eggs every two weeks, and the eggs hatch in 1–3 weeks. Larger than usual snail populations occur approximately every 2–3 years.
- The snail thrives in moist environments, soft-leaved vegetation, and loose soil where it gets shelter and food. It eats plant debris and helps decompose it, producing humus. It enjoys nettle and dandelion; however, hairy and hard-leaved plants are not appealing to it.
- Snails can’t withstand dryness, as moving on dry ground is difficult. A long, warm heatwave destroys the eggs.
- Snails spread via soil, plants, plant debris, vehicles, and dumpsters, as well as along waterways.
- In Finland, copse snails are found mainly in the south. Their number has increased in recent years.
Expert: Päivi Korpivaara.
