Why is my Garden Full of Slugs? (7 Ways to Keep Them Under Control)

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I’ve been a keen gardener for many years and have been experiencing a problem recently that many will be familiar with: a growing slug population that is slowly working its way through eating my fruit, veg and plants. So I’ve been looking into what attracts slugs in the first place, as well as finding out about the best ways to keep the slug population in my garden under control.

Slugs like moist, warm and damp environments. Gardens that offer plenty of shelter under pots, containers or rocks during periods of dry weather are especially attractive habitats for them. Add to this an easily accessible and abundant food source, such as general vegetation or fruit and veg crops, and you have the perfect conditions for a slug population to thrive.

You may be surprised to learn that there are typically around 20,000 slugs lurking in the average UK garden! Let’s look in a bit more detail to see what can attract slugs in the first place, and what can be done to manage them and keep them under control.

What Attracts Slugs to a Garden?

Moisture

The number one thing that slugs need to survive is moisture. Slugs are made up mostly of water and have a thin layer of mucus / slime all over their bodies that acts as a barrier to to retain the water and moisture within. In the wrong type of environment it will only take a few hours for a slug to completely dry out and die.

Slugs actively seek out environments that will help conserve their moisture – and this is part of the reason that they are nocturnal. You will usually only see slugs out and about in the evening/ overnight (when the sun has gone down) or during the daytime during spells of very wet or damp weather.

Warmth

Slugs are cold blooded and are only active during the warmer months of the year, typically hibernating below the surface of the soil when temperatures drop below around 5C / 41F. In extremely mild UK winters, if temperatures don’t drop below this threshold, slugs can remain active an breed throughout the season. This can cause a significant increases in the slug population the following year.

A Food Source

Slugs need a food source to survive. Although they will eat things like decaying plant matter, roots and earthworms, they will also turn their attentions to your prized plants, fruit and veg! The more food easily available in a garden, the more slugs it will be able to sustain!

Shelter

Slugs need to take shelter for the majority of the time during the day so that they can preserve the moisture content of their bodies. They look for hiding places where they will both be protected from predators and where there will be constant moisture.

Because they do not have a shell, like snails, they are able to access small and restricted crevices. The ideal shelter is often provided under general garden rubble, large stones, bricks, plant pots and containers. I moved a plastic planting container placed on slate chippings in my garden today and there was a slug sheltering underneath:

7 Tips to Keep Slugs Under Control

There are plenty of different different approaches when it comes to keeping the slug population in check. Here are 7 of the best ways that I have found:

1. Encourage Natural Predators

Predators of slugs in the UK include hedgehogs, frogs and birds. By encouraging these into your garden you will help keep the slug population down naturally.

Maybe you could try feeding birds to attract more into your garden? Or encourage frogs by creating a small garden wildlife pond?

If you have seen a hedgehog in your garden or want a few tips on how to encourage them in, follow this link to our post on hedgehogs!

2. Create a Physical Barrier

Creating a physical barrier around planting and crops is another way that can help keep slugs under control. Two popular options are to use either copper tape or eggshells:

Copper Tape

Slugs experience a reaction when they come into contact with copper so encircling a container, raised bed or even an individual plant with a ring of copper tape acts as a deterrent.

I have used copper tape myself around both raised beds and containers and found it to be very effective.

Click below to shop for copper tape on Amazon:

Eggshells

As a slug’s body is soft and covered in mucus / slime they prefer to travel over smooth, flat surfaces – any rough surfaces are going to be more difficult to move over. Laying eggshells around the circumference of planting that you want to protect can help deter slugs.

I have tried this myself and although it was not 100% effective (some slugs will still travel over rough surfaces) it did have a noticeable effect in reducing their numbers.

If you don’t have eggshells you can try using any other rough material such as sand or slate chippings, for example.

3. Tidy up Your Garden: Remove Debris and Reduce Available Shelter

Removing debris such as unused plant pots, decaying leaves, decaying wood, old bricks and rocks will reduce the amount of shelter available to slugs, which will in turn help reduce numbers.

4. Dig Over Soil in Winter and Early Spring

Slugs lay their eggs in the soil. By turning over your soil during winter and early spring these eggs will be disturbed and exposed which will help reduce the slug population in the coming year.

5. Introduce Slug Repelling Plants

There are certain plants that actually act to repel slugs – due to their smell or texture – and planting these amongst more susceptible plants can reduce the number of slugs in the vicinity. Companion plants to try include ferns, geraniums, rosemary, hydrangea and lavender.

6. Regular Night Time Checks and Manual Removal

By going out with a torch at night, or after sustained rainfall, you can catch slugs in the act of eating and damaging your plants! Doing this on a regular basis and removing the slugs one by one is a surprisingly effective method of control. The more frequently you do it, the less you should find. Personally I check in this way around 2 -3 times a week in the spring and summer.

7. Use a Beer Trap

Beer traps can also be an effective and environmentally friendly method of removing slugs from your garden. Once you have set a beer trap up you will need to clear and replenish it regularly. Beer traps tend to only cover a small area so you will usually need to set up multiple traps.

The best beer trap that I have come across is the Slug X trap. This trap can be used on any flat surface (including patios) and I have had a lot of success with it. You just need to fill up the beer wells fully and remember to clean it out regularly.

Slug X traps are available on Amazon here:

And Finally…

Two other methods of control that have been used by some gardeners are slug pellets and salt.

Slug pellets that contain a pesticide called Metaldehyde (which can be damaging to other wildlife such as hedgehogs and birds) have now been banned in the UK, but it is still possible to get ferric phosphate based pellets which, whilst still controlling slugs and snails, are safer and much less harmful to the environment.

Another method of control is to cover the slug in salt which will draw all of the water away from it – enough salt and it will die of dehydration. The problem with this method is that the salt will dissolve into the soil, potentially impacting plants and other wildlife in your garden.

Conclusion

Although it may not be possible, or desirable, to completely eradicate slugs from your garden, by following these tips you should now have the tools in your armoury to help keep your garden’s slug population under control!