Slugs. The tiny garden invaders that can turn your lovingly grown lettuce into lace overnight. If you’ve ever woken up to nibbled leaves and vanished seedlings, you’re not alone! Slugs are a constant battle at The Gardeners Co. too, and it's liklely the no. 1 question we're asked. So, we've been doing a trial all year to figure out what works, and what is complete nonsense.
Why Are Slugs a Problem?
Slugs are part of a healthy ecosystem, helping to break down decaying plant matter. The trouble is, they don’t stop there; they also love tender new growth, young vegetable plants, and soft leaves. A single slug can consume several times its body weight in one night, which is why they can do so much damage in so little time.
Slugs thrive in damp, shady conditions and are most active at night or after rain. They lay hundreds of eggs in the soil, which means if you’ve seen a few, there are likely many more nearby. Instead of trying to eradicate them completely (which is impossible!), the goal is to manage their numbers and protect your plants.
Natural Ways to Deter Slugs
The good news? You don’t need harmful slug pellets to win the battle. Here are some effective, eco-friendly ways to keep them at bay:
1. Create Slug Barriers
Slugs have soft bodies, which means they don’t like crawling over rough or irritating surfaces. Try these natural deterrents:
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Sheep’s wool – The dry and prickly fibers are irritating, making a very unappealing barrier. Head Gardener Shan swears by sheeps wool after it saved her flower farm field of over 100 dahlias one year. It must be unprocessed (not like the stuff you get in food delivery boxes) as the lanolin in the fibres are part of what keep the slugs at bay.
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Crushed shells and eggshells – Sprinkle around plants to make a prickly barrier. At The Gardeners Co, we’re big fans of ‘Shell on Earth’, who crush old whelk shells down to provide a barrier layer that slugs dislike, it's not a perfect method though and you'll likely see some damage still. Added bonus, it looks beautiful in pots and beds!
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Copper tape – A great option for pots and raised beds. The reaction between a slug’s slime and copper gives them a tiny electric shock, discouraging them from crossing. We recommend using electricians copper tape, it's thicker and more effective!
2. Use Companion Planting
Certain plants act as natural slug repellents. Try planting:
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Lavender, rosemary, and sage – Slugs dislike strong scents.
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Marigolds and nasturtiums – These can be used as ‘sacrificial plants’ to lure slugs away from your vegetables.
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Chives and garlic – The strong sulphur compounds in these plants help deter slugs.
3. Water Wisely
Since slugs love damp conditions, tweaking your watering routine can help reduce their numbers.
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Water in the morning rather than the evening -this gives the soil time to dry out before slugs become active at night.
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Avoid overwatering - keeping soil on the drier side can make it less appealing to slugs.
4. Make DIY Slug Traps
Slug traps can help remove existing slugs from your garden. Here are a few ideas:
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Beer traps – Sink a shallow container into the soil and fill it with beer. Slugs are attracted to the smell and fall in. A gruesome but effective method!
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Wooden boards or damp newspaper – Leave these out overnight, then collect and relocate the slugs in the morning.
5. Encourage Natural Predators
Nature has its own pest control system that can be utilised to help:
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Frogs, toads, hedgehogs, birds, and ground beetles all love eating slugs.
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A small wildlife pond or a few log piles can encourage slug-eating creatures to visit your garden.
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If you happen to keep chickens or ducks, let them patrol the garden - slugs are one of their favourite snacks!
6. Use Nematodes
Nematodes are microscopic worms that naturally occur in soil and act as a biological slug control. We're huge fans of Ladybird Plant Care for all of our biological pest controls.
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How they work – These tiny organisms actively seek out and infect slugs with bacteria, leading to their natural decline.
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How to apply – Mix nematodes with water (according to the instructions) and apply to moist soil where slugs are active.
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Best time to use – Apply in spring and autumn when soil temperatures are a bit warmer.
7. Hand-Picking (Yes, Really!)
If you’re up for it, an evening slug hunt with a torch can be surprisingly effective. Simply collect the slugs and relocate them far away from your plants, or feed them to birds or chickens.
8. Protect Young Plants
Seedlings and young plants are the most vulnerable, so take extra precautions:
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Use cloches or cut-off plastic bottles to shield young plants.
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Raised beds can make it harder for slugs to reach your crops.
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Mulch carefully - avoid damp mulches like straw if slugs are a big problem in your space.
Finding Balance in the Garden
The aim isn’t to eliminate slugs completely, that would be impossible and unhealthy for your garden’s ecosystem. Instead, focus on keeping their numbers in check and giving your plants the best chance to thrive. A mix of these natural methods should help you strike that balance, keeping your garden productive while working in harmony with nature.
So next time you spot a slug, don’t despair - just grab your coffee grounds, invite some helpful frogs in, and let nature do its thing.
Garden getting overrun with pests? There are other natural pest control methods discussed in our Introduction to Biological Pest Controls blog.