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Is it possible to hold back the slugs?

Slugs – a gardener’s worst enemy. There are a number of methods out there to stop them in their tracks, be it environmentally friendly or chemical, but have you ever found one that does the trick?

Ask any gardener what their worst pest is and slugs and snails will feature high on the list. Three quarters of Which? Gardening members told us that they’re a real problem.

The tell-tale slime trails across your decimated plants, the stump-like remains of your seedlings and the gaping holes in your hosta leaves all show that slugs and snails have been busy eating your carefully tended garden. The damage is enough to make you hop round the garden in fury.

Barriers to protect your crops

In an attempt to get rid of slugs and snails gardeners use barriers, pellets and nematodes with abandon. But is it time to throw in the towel and make peace with these pests?

Our recent tests showed that environmentally friendly barrier methods are not much better than leaving your plants unprotected, especially when you factor in the faff of installing the barriers.

We tested plastic barriers with sharp teeth that were supposed to deter snail, but the pests simply hurdled the obstacle by arching their bodies. Granules that were supposed to be too sharp to crawl over became soggy and sticky when watered. Copper is another deterrent but the tape we used was breached within days.

Some barriers showed promise, such as wool pellets that created a hairy mat, or a gel that made a slug turn through 180 degrees and head off in the opposite direction, but even these failed to protect our seedlings for long.

Home-made methods, such as egg shells, beer traps or coffee granules may be cheap alternatives, but our poll told us most members have had poor results. Ducks and geese were the best performers, although these have to take their place in the food chain and are often fall prey to foxes.

Biological and chemical controls

Then there’s Nematodes which seem to work well on slugs, but not on snails. These tiny parasitic worms are watered onto the soil and work their way into slugs where they infect them with a lethal fungus. But they’re a nuisance to buy and use as they have to be ordered online and then kept in the fridge until the weather and soil temperatures are right.

The problems with pellets containing metaldehyde are well known, such as causing harm to birds and pets if eaten in large quantities. It’s also known to pollute water when used in high doses in agriculture. Some experts even predict it may be banned in the UK if the problem is not controlled.

Ferric-phosphate pellets are certified as organic, but some research suggests that it may cause problems for earthworms and alter the chemical balance of the soil.

So it looks as though we have three choices: using remedies that may be less than environmentally friendly, carrying out night-time raids with a torch and bin bag or learn to live with slugs and snails. Which method do you use? Or do you have a secret tip that we’d all love to to know?

Maewyn says:
29 March 2015

I’m a slug patroller, like many others. Wearing disposable latex gloves prevents hands from becoming horribly slimy. Drop the slugs and snails into very hot water, and they die instantly. Then throw the lot into the compost, and the slugs can feed the garden rather than eating it. If you use salty water it will slow down the composting process as the salt will kill of the bacteria and other helpful composters.

Yoga monkey says:
21 July 2015

Can anyone tell me if slug/snail etc bitten leaves make the vegetable more nutritious? I mean, are there any health benefits to a plant being bitten into by an invertebrate scavenger?
Someone told me this snippet recently and I wonder if there is any truth behind it?
Plants do produce their versions of an immune response when attacked or predated, lectins or plant hormones are there to deter the consumption of their seeds etc but does a bug biting into a leaf cause the release of healthful chemicals?
A positive spin on slug attacks perhaps!


Great idea Yoga monkey! Although I have to say my first thought was whether I would want to eat anything with slug slime on it, as slugs and snails are chock full of parasites and bacteria.
So, I checked with our slug experts at the test lab and they told me that when a plant is eaten by a pest, including slugs and snails, it produces two plant hormones as a defense mechanism: jasmonic acid and salicylic acid.
They are both naturally produced hormones and have numerous different roles within plants, so are present in many plant-derived foods that we would eat anyway. Jasmonic acid seems to play a part in the production of tuber in potatoes. Salicylic acid is involved in a whole range of plant processes, including photosynthesis and nutrient take-up, and can be found in a wide range of foods from berries to peanuts.
Of the two, salicylic acid seems to be more beneficial for health and it used as an ingredient in anti-inflammatory drugs and as an ingredient in topical creams for conditions such as psoriasis, acne and corns.
Jasmonic acid is applied to some seeds as a pest deterrent.
So, the long and the short of it seems to be that we probably have better sources of salicylic acid available in the foods we already eat, but at least we don’t need to turn our noses up at slug nibbled veg.


And of course salicylic acid is the forerunner of aspirin. I did see a claim about 20 years ago in the New Scientist that eating trace elements of salicylic acid was mans normal diet and that eating supermarket specimens was stopping us getting this boost . This on the basis that some plants having never been attacked had limited need to defend itself by producing the acid.

There is some research published this month on how salicylic acid actually works :
” Scientists are finally getting a glimpse into how defense hormones shape plant health both above and below the soil, thanks to a study published today (July 16) in Science. The results show how an Arabidopsis thaliana defense hormone, salicylic acid, which helps protect the health of the plant’s shoots and leaves, also guides the growth of microbial communities in and around its roots.
“This is the first study that really tied this phytohormone to the microbiome associated with the root,” said Xinnian Dong, a professor of biology at Duke University who was not affiliated with the work.
Commensal root microbes can confer numerous benefits to a plant, including increased tolerance to environmental stressors like heat, drought, and acidity, and aid in the plant’s acquisition of nutrients. However, little is known about how plants might influence their underground microbial communities, or how a plant’s immune system interacts with the bacteria it encounters in the soil.”


Snails and slugs have been a serious issue for my garden for years. I am really against the usage of chemicals and that is why I am always looking for new solutions! Thanks for the article! Here is another one that I find helpful :http://www.houzz.co.uk/ideabooks/57663016/thumbs/protect-your-garden-from-slugs-and-snails

Kerwin Maude says:
6 May 2016

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Sprinkle table salt around your garden or flower plants at least 3 feet away from the plants. Sprinkle it lightly in dry weather and reapply after rainy periods, common sense. The slug will self implode into a gooey glob; commerical baits might be effective but salt is cheap and very effective. Slug baits bought at retailers might have issues for pets, curious kids and plants, but ask an expert. If you want to whack pesky ants, try 50/50 mix of borax and icing sugar, it works like a charm but ants are resilient buggers. If you want to kill unsightly weeds, vinegar is great and I use recycled window bug screen fabric or new defective rolls to layer them at least two sheets thick around my shrubbery and it works beautifully. They are porous and permit air and water but weeds struggle to pop through, and landscape fabric is costly. My landscape project has been weed free for over 9 years, try it to reuse and recycle window bug screens instead of them in landfills.


I’ve never tried it myself, but some people eat snails. As a child, I did eat periwinkles, and that’s maybe similar? Anyway, I have spent around twenty very early mornings (between the end of June and now, at about 5am or earlier) collecting snails from my garden and helping them migrate to a nice grassy area of parkland across the road. I haven’t injured them in any way if I could help it, and if seagulls and magpies began to be seen more often on the grassy area, well…. Any snails and slugs that tried to cross the road again were gently redirected by me, and now the population in my garden is well down, and I don’t see any on the grassy area either.


I’m not too bothered bu slugs so long as they stay in the garden.

Post-uni, I rented a terraced flat in West Jesmo