Slugs hate dry, rough, or sharp conditions, strong smells like garlic and coffee, and substances that dehydrate them (salt, diatomaceous earth) or give an electric shock (copper), as they thrive in damp, dark, moist environments. They are deterred by coarse textures (wool pellets, egg shells, pine needles) and plants with tough leaves or strong scents like lavender and rosemary, making dry, sharp, and strongly scented barriers effective deterrents.
Discourage slugs by creating lighter, drier conditions.
Prune lower tree branches and shrubs to allow more sunlight to reach plants and soil. Divide or thin plants to improve air circulation, allowing the soil surface to dry out. Stake plants and prune lower leaves to raise plants off the soil and away from slugs.
Pouring salt on a slug will kill it in a matter of seconds, however, it generally takes quite a bit of salt to do so. The salt kills the slug through osmosis – it draws water from inside the slug and rapidly dehydrates it.
Tea and coffee sprinkled around plants can also help deter slugs and snails from getting at them, as it is apparently off-putting to the creatures. Other food waste items could help your garden, such as banana peels, which contain nutrients such as potassium, calcium, and phosphorus.
Slugs hate strong-smelling plants, and one of the most popular plant scents that is slug-resistant is lavender. Lavender has very low toxicity to humans, making it an ideal choice when it comes to repelling slugs from your home. Other popular choices include rosemary.
One of the most common slug deterrents hack you've probably come across is the old crushed eggshells trick!
Slugs are nocturnal, typically feeding from dusk to dawn. They may also feed during rainy or overcast days. During the day, slugs hide in soil crevices and under crop residue, which is why reduced- and no-till fields are at greater risk for damage (Photo 4). They prefer high humidity and temperatures below 70°F1.
Diluting brewed coffee with an equal part water is plenty to do the job. Coffee grounds have been recommended in the past as an organic method to keep slugs and snails out of your flower and vegetable beds. Grounds will repel slugs, but the USDA research team confirms that a caffeine solution is more effective.
And they really dislike certain odors. So, plant some fragrant things in your garden box that they hate: like mint, fennel, geraniums, garlic, thyme, marigolds, and foxglove. But if there's a huge slug infestation, that won't be enough. Here's my recipe for a homemade garlic spray.
Repellent Metals
Copper and zinc are toxic to slugs, and they will avoid contact with these metals. So, placing a strip of copper tape around slugs' usual entry points (either internally or externally) should keep them away. Online shops usually sell copper tape for around £1 per metre.
Slugs are active for most of the year but are a particular problem in spring, when there's plenty of young growth for them to eat. They are mostly active after dark, especially when it's warm and damp. In hot, dry weather they bury themselves in the soil or hide in cool, dark places to avoid dehydrating.
Baking soda can deter some garden pests, such as slugs and ants. When sprinkled around plants, it creates an inhospitable environment for these pests.
They seek moist, shaded areas during sunny days and hibernate in topsoil during cold weather. Indoors, they are attracted to damp areas and leave shiny silvery slime trails.
Copper tape. The use of copper is also believed to be a good remedy for slugs. Copper is considered to be a natural slug repellent as the mucus they secrete from their body (their slime) reacts with the metal, producing a tiny electric shock.
Control strategy
Good seedbed preparation is crucial in controlling slugs. Start by removing weeds and green cover as potential hosts and feed source for slugs. The aim should be to have a fine firm seedbed which restricts slug movement making it difficult for them to find seed and seedlings.
Adult slugs overwinter and can lay clutches of eggs when environmental conditions are right. A slug's life expectancy is from 6 to 12 months, and some up to 18 months.
Repellents made from yucca extract are said to be a barrier slugs and snails will not cross. A ring of sharp grit, crushed egg shells, pine needles, coffee, ash or soot around a plant can help keep slugs and snails away. A mulch of cocoa shell is also worth a try.
As vinegar is mildly acidic, it will kill any snails or slugs it touches. However, vinegar is toxic to vegetation, so only spray snails or slugs that haven't yet reached your plants.
Slugs seem also to be put off by the strong scent of Lavendula (Lavender), Rosemarinus (Rosemary), Foeniculum vulgare (Fennel) and Phlox paniculata (Perennial phlox). There are so many plants that slugs simply can't stomach. In fact, that you could plant your entire garden with slug-hated plants.
Plants that dislike coffee grounds are generally those preferring alkaline soil, like lavender, rosemary, thyme, and asparagus, or moisture-sensitive types like succulents, cacti, and orchids, as grounds can create acidity, retain too much moisture, attract mold, and compact soil, inhibiting growth. Other vegetables like spinach, cabbage, and peppers, plus young seedlings, should also avoid them.
Slugs and snails like cornmeal even more than breadcrumbs or beer: you'll attract tons of them. They eat their fill and then leave your plants alone for a while. Cornmeal is used as chicken feed, so you can probably find it at a pet store for a good price.
The hardest pests to get rid of are generally bed bugs, cockroaches, and termites, due to their resilience, rapid reproduction, and ability to hide in tiny, inaccessible spots, often requiring professional intervention and specialized methods like heat treatment or advanced baits. Rodents (rats/mice) and ants are also extremely challenging because of their intelligence, prolific breeding, and complex colony structures.
Slugs are known to feed on a wide range of plant materials, but they particularly favor moist and decaying vegetation. They also have a preference for fruits and vegetables such as strawberries, lettuce, and cabbage.
Bathrooms, with their high humidity levels, attract slugs. These creatures can climb walls and travel across ceilings to reach their destination. Their slime trails, a mix of mucus, proteins, peptides, and minerals not only facilitate their movement by reducing friction but also help them adhere to vertical surfaces.