/ Home & Energy

Slug-armageddon – the battle all gardeners face

Slug in grass

When I finally meet my nemesis, I think it will probably be slug-shaped. I’ve had a terrible time with them. Have you had problems with slugs this year? How do you plan to cope with slugs next year?

There’s a reason why slugs will always feature near the top of any gardener’s list of adversaries. We seem to share pretty much the same tastes, and if I like growing it, I’m sure they’ll enjoy eating it even more.

They are the vandals of the horticultural world and can decimate a freshly planted crop overnight, leaving little behind other than half-chewed stumps, and their tell-tale slimy escape route.

Wet summer brings out the slugs

One of the wettest summers on record has meant that the slugs have had free rein on my plot for far too long. They seem bigger, bolder and slimier than ever and have wreaked havoc with this year’s veg. Early sown salads were devoured overnight and the new shoots of my Dahlias proved to be one of their favourite delicacies.

There are around 30 species of slug in the British Isles, and an average-sized garden may contain around 20,000 of these rampant gastropods.

Recently, there’s been concern over the spread of the ‘Spanish stealth slug’ (Arion flagellus) which is much larger than most of our native slugs, reaching up to 10 inches in length! These invaders hitched a ride to the UK in plant imports over 40 years ago, and have steadily spread. They are self-fertile, can lay between 350-500 eggs (far more than our native slugs) and their immense size has meant that not much is prepared to eat the blighters.

How to get rid of slugs

When we surveyed 2,000 Which? Gardening readers, we found they used a wide range of methods to control these pests. The most popular were copper barriers around pots and plants, ducks and geese, nematodes and even removing them by hand (yuck!).

I have experimented with lots of DIY methods, like setting beer traps (which seemed like a waste of good beer) or putting a barrier of oats around my plants (to interfere with the slugs’ slime glands), but none seemed to be particularly effective.

I once experimented with copper rings around my Hostas, but found that as the leaves grew over the barrier they provided a handy bridge for the marauding molluscs to breach my defences. I have even heard of coffee grounds being used as a mulch around plants to deter slugs who apparently don’t share my caffeine habit.

Even with such an array of ways to kill slugs, lots of gardeners will immediately reach for the slug pellets when they suspect an attack is imminent, if only for some peace of mind.

Organic or non-organic slug pellets

Our trial last year found that organic slug pellets were just as good as non-organic ones in the battle against slugs and snails. As a result, we’d recommend you go with organic pellets, as unlike those based on metaldehyde, they are approved for use by organic growers and pose no threat to people, pets or wildlife.

Given the ideal conditions for a boom in slug numbers, it’s hardly surprising that most slug pellet manufacturers have reported an increase in sales this year. B&Q claims that sales of slug pellets were up 51% from the same period last year.

Resourceful and pragmatic, gardeners will always have to expect a few losses (and even complete failures), but this year I have to admit I’ve struggled to grow enough to feed both of our appetites. In future I may find myself reaching for those little blue pellets. How about you?


I am a little surprised that ferric phosphate is effective as a slug killer but harmless to wildlife. Metaldehyde can certainly kill hedgehogs and birds that eat poisoned slugs.

I would be much happier using some form of biological control that would target slugs and snails but I don’t know how effective these are or whether they are sold in the UK.

par ailleurs says:
9 October 2012

I’m normally pretty firm on organic gardening and usually I have no overriding pest problems. Things mostly find a balance; you lose a bit but still have sufficient to eat and freeze, make jam or chutney. This year has however been the worst I can remember in 35+ years of gardening. It wasn’t just the wetness but the cold interspersed with odd weeks of warmth which lulled plants into a false sense of security. Then it was warmer and damp which is slug heaven.
Too late did I finally realise that the ferrous based pellets are both effective and harmless to other creatures. I’d rather starve (or buy at Tesco!) than use metaldehyde. I like my garden to be full of wildlife too and some slugs, snails and insects are necessary for that.
So where to next? I shall continue to use the organic pellets most certainly if next year is as bad. I shall also use copper tape around pots and I’ll still use beer traps. I know it seems like a waste but you only need the cheapest canned bitter, not the stuff you’d drink yourself. Finally there is hand picking. We take them in a bucket to a far corner of the plot where they won’t do so much damage. Soft? Yes, but otherwise you’ve got to squish them and they are mighty unpleasant.
So that’s next year’s plan unless the dreaded Spanish slugs arrive round here. If that happens I’ll probably move to a flat with no garden.

Maybe Tesco could do us all a service and put their ultra-cheap loss leader lagers and beers in the gardening department for use in beer traps.

Graham says:
28 May 2014

I have to grow my veg in pots and have been told to use vaselene around the top of the pot.Has anyone tried this, and was it affective.

Gerard Phelan says:
12 October 2012

When you have found your slug you could just sprinkle it with salt. The slug dies and the body is nicely seasoned for consumption by other wildlife!

Like James, I have seen a lot of slugs in the garden this year, and plenty of snails too.

Please tell me that they grow up to 10 cm rather than 10 inches. After all, we have gone metric. The thought of giant gastropods alarms me, even if they can only move sluggishly or at a snail’s pace. 🙂

If you keep ducks, they will feed on slugs in the garden, as well as scraps from the table. There are drawbacks – like hens, they can be destructive where newly planted seeds are concerned. The answer would be to block access to areas where seedlings have been planted. Your own Organic duck meat on the table is delicious. As everything needs to be recycled, this is probably the best way to deal with slugs.

Normally I try to live and let live and tell myself that they are part of the circle of garden life and that they provide food for something else.

But this year they mounted such a bold and greedy campaign on everything that I was trying to get looking lovely for my husband’s birthday party that I had to change tactic. Particularly as by mid-July they were swarming round the garden in broad daylight and had got so ravenous they even started eating the buddlia and ground elder (they’d be fine if they started with the latter first…).

I’ve tried, beer traps – you get foul stinky beer to dispose of, full of good garden insects and beetles. I’ve tried green plastic collars – as James says as soon as a leaf touches the other side they use it as a way to a tasty treat. I’ve even tried lining them up in front of a frog that I found -but he paid no attention whatsoever.

This year I found that bodily removal from the garden was the only way to get on top of the problem. I started by just going round and gathering them in a flower pot and throwing them in the green waste bin – but unfortunately my husband isn’t careful about closing it when he recycles, so I’d spend an hour rounding them up, just to find a trail of them legging it out of the bin as soon as he went near it.

So with slugs and a husband to get the better of I started enclosing them in non-recyclable containers that they couldn’t get out of (slugs not husband) – plastic takeaway containers and high street frothy coffee shop cups (these are best for snails because slugs can squeeze out through the drinking spout).

I think the problem was worse this year because the field behind our house, which is usually grazed by horses, was left to grow wild this year. At one point, I was removing more than 20 slugs and snails from my leeks every time I walked past their bed.

But by diligently removing all slugs and snails that I found on my daily snail patrols I gradually went from finding 250g of prime fat slugs per patrol to having to search through the day lily leaves to find the tiniest little snails.

Finally when I had finally got on top of them I used a very light scattering of organic pellets to take care of the ones that normally hide under the soil until night, and generally things have been quite a bit less nibbled recently.

Generally I would prefer not to spend my time picking slugs up, but I do think that it was the only effective way to get rid of them this summer and throwing them in the bin and knowing they wouldn’t reappear was a very satisfying experience.

Brian Bliss says:
8 November 2012

After Which showed that organic pellets were as effective as metaldehyde ones I purchased some for use this year but also used up some of the metaldehyde ones I still had. Has anyone else noticed that when you use metaldehyde you can go around next morning and collect slime’d out slug bodies for disposal but when you use the organic pellets there are no signs of any dead slugs around next day or any time after. What has happened to them assuming the pellets have worked? Do we need to see to believe? With so many slugs this year it has been difficult to compare how much protection the two kinds of pellets have given.