We don’t like using slug pellets as they are (unsurprisingly) very toxic. They contain the pesticide metaldehyde (usually dyed blue). It kills slugs, snails and anything that eats them, including frogs, toads, hedgehogs and birds as the toxins ‘bioaccummulate’, intensifying up the food chain. Even if you can ensure that wildlife don’t eat the pellets themselves, it is impossible to prevent them from eating the poisoned slugs and it’s one of the biggest threats to hedgehogs and song thrushes. Slug pellets are also poisonous to chickens and pets.
So over the years we have developed the following chemical-free, wildlife friendly techniques for protecting your garden from slugs. If you have any more tips to add to the list please comment below!
The Royal Horticultural Society has so many enquiries that they are doing a formal scientific test of traditional remedies to see if they actually work. They also point out there are about 40 different species of slugs and some are actually good for the ecosystem.
Please note that because home remedies like coffee grounds or soap haven’t yet been researched as a pesticide, it is illegal under EU regulations to use them..! According to this Independent article Bob Flowerdew, a regular on Radio 4’s Gardeners’ Question Time and the author of books on organic gardening, said: “Regulations are an ass, but they haven’t led to prosecutions. I cannot recommend that anyone breaks the law, but I can point out that, in other countries, people do use coffee grounds.”
1. Slug Removal
a. Go into the garden when it’s dark with a torch and pick them all up
b. Near your beds, place tarp/flat stones or tiles that the slugs will hide under and simply pick them off in the morning
2. Physical Plant Protection
We’ve tried cut-off plastic bottles and sheep’s wool with little success to be honest (as above photo illustrates!).
However these have good reputations:
slug collars
copper tape (only while it is 100% intact)
copper mesh
3. Potions & Powders Slugs Don’t Like
There are some things you can spray or put round your plants that slugs don’t like the taste of:
1. Coffee grounds -according to this ScienceNews article the neurotoxic caffeine destabilizes the mollusks’ heart rate, so coffee grounds and leftover coffee have been reported to be deadly to slugs (but not de-caf).
2. Garlic Wash – Una Dunnett’s Garlic Wash recipe for Hostas: Crush two bulbs of garlic, steam or boil them in two pints of water for three to four minutes until they’re blanched, Strain mixture and make back up to two pints. Leave it to cool, then mix one tablespoon into a gallon (3.8l) of water, and sprinkle on to hosta leaves in dry weather. Re-apply after it has rained.
3. Soapy Water
4.Salt
5. Diatomaceous Earth – reports say this works when it is dry but this website is concerned about the harm it causes to benefical insects that eat slug eggs.
6. Crushed Eggshells – bake off the membranes (20 minutes at 150 degrees) and don’t crush too finely. You want to keep the sharp edges.
7. Ash – from a BBQ or a fire.
4. Out of reach
We’ve had some success suspending planters of lettuce off the ground. These are a couple of old recycling baskets attached to an old sewing machine table base. Simply putting pots on chairs might help.
Hanging baskets should achieve same affect.
But don’t forget – when you transplant a plant into a safe new position there’s a chance you’ve taken a slug with it in the soil so check the plants for stow- aways the first couple of nights.
5. Grow plants that slugs don’t like to eat!
We’ve found that the following plants are safe from slugs: rocket, land cress, nasturtiums, tomato plants, basil, leeks, chickpea plants.
6. Tasty Traps
Beer Traps
You can use beer or make a potion that slugs find irresistible and then drown in. Thanks to PP reader Joan for sharing a Telegraph recipe from a few years ago that really works well:
Mix 2 cups warm water, 2 tbsp flour, 1 tsp sugar and half teaspoon yeast. Pour into shallow plastic container and leave near the affected plants.
Joan makes it in industrial quantities: 80g flour, 20g sugar, 10g yeast and 1 litre of warm water
Bran Traps
7. Nematodes
8. Organic Pellets
9. Strulch
10. Encourage slug predators
Create habitats that will support slug predators like beetles (eat slug eggs), birds, toads, frogs, hedgehogs, shrews, moles and slow worms. Plant extra plants because you will expect to lose some leaves.
4 Responses
Wood ash is very effective as it reacts with the slime to burn them so they won’t cross it does make soil more alkaline so I don’t use on my lime soil.i have used organic slug pellets for twenty years.very effective.and harmless to other creatures
I find broken egg shells work in a circle around my dahlias, although I notice you say that you don
Thanks Mary – I know other people who have success with egg shells so I will try again. If you could send me a photo of yours to penny@pennypost.org.uk then I know what size to crush them.
We use very cheap and horrible (nameless!) beer….in traps as per number 6…..we use old soap powder dispensers and bury them to ground level….catches literally dozens every night.