10 All-Natural Slug Repellents
Slugs aren’t just gross and slimy, they’re also harmful to nearly every type of plant you might have in your garden.
They live in damp areas, and come out at night, especially when it has just rained. One slug can eat twice his body weight in just one night, meaning one family of slugs can destroy a flowerbed in a matter of days!
As much as we may hate slugs, however, it’s important that we don’t use harmful chemicals to get rid of them at the expense of other wildlife. Many commercial slug repellents use Ferric Sodium, which is harmful to other animals, including pets, and beneficial pollinators like bumblebees and butterflies.
Luckily, there are many all-natural methods of repelling slugs, that are cheap (or even free) and safe for beneficial wildlife.
Beer has been a popular method of trapping slugs for many years. All you have to do is put a couple inches of beer in a shallow container, then bury it in the soil up to the rim. Slugs will be attracted to the beer, then fall into the container and drown.
If you have easy access to seaweed (such as living near an ocean or lake) this is a free way to keep the slugs out while also nourishing your plants. Lay the seaweed around your plants in piles 3-4 inches deep. When it dries up, it will be very salty and rough, which will deter slugs. As it decomposes, it provides lots of nutrients to the soil to help your plants grow even stronger!
- Diatomaceous Earth
DE (or “insect dust”) is a powdery material made up of the crushed skeletal remains of microscopic creatures. The granules have jagged edges that lacerate slugs’ skin, causing them to dehydrate. Simply sprinkle it around your plants during dry weather, and it will kill or deter any slugs that come near it.
- Red Clover
This is an easy, fast-growing plant that slugs love to eat. You can buy it in bulk, or as “seed bombs” to spread the flowers around your garden. Not only are they beautiful, but slugs will be drawn to them and away from your other plants. Once one of your clover plants has been destroyed by the slugs, you can mix the remnants in with the soil for extra fertilizer, and more clover plants will grow in to fill the space.
I wasn’t sure if I should mention this option or not, since there is some debate over whether or not it works. Many people swear that using copper strips or copper tape to form a barrier around plants will keep the slugs away. However, copper metal is non-toxic, even to slugs. And the myth that copper will shock slugs when they touch it has been proven false. It seems that the only reason some slugs will not go past copper barriers is because it’s a pain for them to climb over any barrier. Using cardboard or plastic barrier walls would probably be just as effective.
At least this method has been proven by science! In 2002, a scientific journal published a study proving that caffeine is toxic to slugs. Coffee grounds are also biodegradable, so sprinkling them around your plants is beneficial in two ways: it will repel slugs, and break down in the soil for easy (non-existent) clean up!
- Egg Shells
Egg shells affect slugs the same way Diatomaceous Earth does, by lacerating the slugs’ skin as they move over it. Simply crush up the egg shells into small pieces and sprinkle them around your plants. Like coffee grounds, the egg shells will break down into the soil and provide fertilization.
- Citrus Rinds
Some people would rather trap slugs than harm them, and one way to do that is with grapefruit halves. Place it upside down (with the fruity part face down), and the slugs will be attracted to the fruity smell. They’ll climb in there, and then stay there to protect themselves from the light in the morning. Then you can pick up your slug-filled grapefruit (yuck!) and get rid of it however you please.
- Adjust Your Watering Schedule
If you don’t want to kill or trap slugs, you can try to avoid them altogether by changing your watering schedule. Slugs are attracted to moist environments, and they come out at night. If you stick to watering your garden in the early morning, the ground will be dry by evening, and slugs won’t want to come near it.
- Hand Picking
This is the tried and true method of getting rid of slugs. If you see them in your garden, pick them up! You can toss them in a bucket of soapy water to kill them, or gently place them in your neighbor’s yard if you’re feeling humane (and spiteful). You can combine this with the grapefruit trap, or place a flat wooden board outside for the slugs to hide under. You’ll find most of them in the pre-dawn hours, or at nightfall.