‘They’ve been something else this year’: slugs wreak havoc on UK gardens | Gardens

There are about 150 species of slimy molluscs in the UK and while not all of them have a taste for plants, the wet weather conditions in spring and summer has led to slugs causing havoc in gardens, balconies and fields across Britain.

Social media has been inundated with people complaining about the amount of slugs cropping up in their green spaces, and desperate for tips on how to get rid of them.

“They have been something else this year,” one user comments underneath a video where she pans across a small patch of grass ridden with slugs. “They’re horrible and they’ve decimated my tomatoes and peppers. Hate the slimy demons,” another comments.

A mild and moist spring and relatively cool start to the summer have created the ideal conditions for slugs to thrive, says Dr Andrew Salisbury, the head of plant health at RHS Garden Wisley.

“Slugs and snails are particularly active when it’s mild and damp and so we can be certain they are more active and more visible,” he says, “but whether there are fundamentally more of them, we cannot say.”

And people aren’t just turning to social media for advice about slugs – the RHS’s garden advice service has been swamped with pleas for help. “We saw a huge peak in slug inquiries in March, April and going into May … we saw three times as many slug inquiries in March this year compared to 2023,” Salisbury says.

“Sometimes it’s just a pure diagnosis, so people don’t actually know that it’s slugs that cause the damage … they are asking us what they can do about the damage because in some cases, people do lose entire plants, or you just put your lettuces or your beans out and they disappear overnight,” he says. Otherwise, they are looking for advice about how to deal with them.

Lewis Normand, the president of the Royal Caledonian Horticultural Society and professional horticulturist, says overnight rain creates an environment where garden molluscs can eat plants while we sleep.

“Vegetable growers in particular have been affected, with personal experience of courgettes, squash and young tomato plants being chomped on and either damaged or completely eaten earlier this summer,” he says.

And people who have balconies also have to accept a degree of slug damage. “It’s amazing how high they can actually climb,” Salisbury says. “If you look on a damp wall, you can actually see slime trails going right the way up to the roof sometimes.

“And once they’ve found something they like, they will stay around and go and hide in the soil during the day.”

Slugs are not only a problem in the home – they are also the biggest agricultural pest in UK farming. “The damage that slugs do is very, very early on in the crops life, when the seed is just emerging or even before it’s emerged, they’ll hollow out the seed,” Tom Allen-Stevens, the founder of the British On-Farm Innovation Network (Bofin) that is leading a project called Slimers, which looks into sustainable methods to control slugs on farms.

“We get asked, are slugs that bad? And yes, they are. They’re actually a nightmare,” he says.

The study is focused on the Deroceras agreste, or grey field slug, which eats the most young crops in fields. The Arion vulgaris, more commonly known as the Spanish slug, and the Arion ater black slug, are the species often doing damage in gardens or balconies.

But is it justified to take measures to get rid of them completely? “What we often say is, it is a bad year. Accept that and tolerate some damage,” Salisbury says.

Some people use eggshells, grit, and pellets to try to get rid of them, but many barrier methods are not scientifically proven to be effective. Nematodes are also often used, which affect only molluscs, but they kill all slugs and snails – even the harmless ones that are important for the ecosystem.

Salt is another popular choice, but is “incredibly cruel”, Salisbury says, advising against it. “Essentially, the slugs die by rapid dehydration and chemical burns.

“Also, if you’re putting large amounts of salt on your soil, it’s no good for the soil or the plants. So actually, salt is potentially more harmful because it’s so indiscriminate.”

Having a pond in your garden is great, he says, because amphibians feed on slugs. Other natural methods such as introducing some leaf litter can encourage other predators, such as hedgehogs, that eat the slugs and snails.

If you want to follow the farmers, you can try consolidating the soil, which removes some of the cracks in the soil the slugs burrow down into, Allen-Stevens says. “Some farmers swear by it, but i’m not sure how effective it would be in a garden … it’s about avoiding the really cloddy soils, which is not so much of an issue on balconies.”

Normand recommends trapping molluscs in jam or beer in half-buried jars, and discourages slug and snail killers due to the toxins they contain. “If you own ducks or chickens, they make light work of slugs and snails,” he adds.

“Personally, I accept that sometimes you win and sometimes you lose,” he says. He chooses to pick off slugs or snails from his plants by hand.