We’ve been waiting for rain for a long time, but I doubt we want it as much as the slugs and snails that have been hiding underground. As soon as moisture seeps into the soil, they will wake from their slumber and make a beeline for our plants.
It seems a shame that those few plants that have survived the relentless heatwaves are now destined to be an entrée. So, we’ve spoken to the experts to find the best ways to get ahead of the game and slug- and snail-proof your plants before it’s too late. Here’s what they recommend.
Where are the slugs and snails?
According to Adam Hart, professor of conservation ecology at the University of Gloucestershire and a Fellow of the Royal Entomological Society: ‘During hot, dry conditions, slugs and snails reduce their activity and retreat into cool, damp refuges; some snails can enter a dormant state known as aestivation. A spell of cooler, wetter weather can then bring them back into activity remarkably quickly.
‘They seek places where temperatures are lower and humidity is higher. That can mean retreating into soil, beneath stones, logs, pots and containers, under dense vegetation and leaf litter, inside compost heaps and into cracks and other sheltered spaces. Slugs can disappear surprisingly effectively into the soil and other damp refuges. Snails have the additional advantage of a shell, and some species can seal themselves inside it to greatly reduce water loss during prolonged dry conditions.
‘This is one reason why people might think their slug or snail population has suddenly disappeared during a heatwave, only to find apparently huge numbers returning after rain. Many haven’t gone anywhere very far – they’ve simply been inactive and hidden.’
So, while slugs and snails may have struggled over the last few weeks, rest assured they’re still ready and waiting for the rain to cue their entrance!
When are slugs and snails likely to emerge?
Moisture is key for bringing slugs and snails to the surface, but a light drizzle is unlikely to do the trick; the soil needs to be watered deeply and dampened enough for them to easily travel through. This is especially the case when you consider how dry conditions have been over the past couple of months.
Adam says: ‘A warm or mild, damp night after rain can be ideal slug and snail weather. Gardeners may suddenly see many more of them, but this doesn’t necessarily represent a sudden population explosion – it’s largely a change in how active and visible the existing population is.’
So, judging by the current forecast, we’re predicting slugs and snails to surface as soon as tonight!
How can I protect my plants from slugs and snails?
Other than the obvious slug and snail pellets, there are a few options open to you if you want to prep your garden for these unwelcome guests.
‘Coffee grounds are high in caffeine, which is toxic to both snails and slugs,’ says Angelika Zaber, gardening expert at Online Turf. ‘Its gritty texture and strong scent also discourage the pests from crawling over. Simply sprinkle them around the plants you want to protect and make sure to reapply after any heavy rain.’
High winds can blow away used coffee grounds at surface level, so it’s worth digging them in. But bear in mind that coffee grounds can be slightly acidic, so avoid burying them around vulnerable or young plants. Coffee grounds are also toxic to cats and dogs, so take care or avoid altogether if you've got pets running around the garden.
Angelika adds: ‘To make your garden less attractive to these pests, you can also use physical barriers, like copper tape around your pots and raised beds, and encourage beneficial predators. Frogs and toads naturally feed on snails and slugs, so investing in a small pond can be a game changer. Birds can help, too, so make sure to put up a bird feeder to encourage them to settle in your garden.’
With natural predators, barriers and deterrents available, there are plenty of ways to protect your vulnerable plants so they’re not such an easy target. Even something as simple as installing a bird bath can make a difference. Or, for an extra layer of defence, you could rub petroleum jelly around the rims of potted plants so they’re less scalable.
Adam adds ‘Reducing obvious daytime refuges immediately around particularly vulnerable plants can help – for example, pots, boards and other objects lying on damp soil can provide excellent hiding places. At the same time, I wouldn't advocate making the whole garden unnaturally bare or removing all leaf litter and dead wood, because those features are valuable habitat for many other garden animals.
‘It’s also worth remembering that slugs and snails are a natural and important part of garden ecosystems. They help break down organic material and are food for many other animals, including ground beetles, frogs, toads, birds and hedgehogs. The aim doesn’t need to be to eliminate them from a garden, but to protect the plants that are particularly vulnerable during periods when slug and snail activity is high.’
So, there you have it; while the thought of slugs and snails emerging from the ground might make you shudder, they’re still essential to the ecosystem. Always deter rather than kill and avoid any methods that are cruel. It’s worth putting a few deterrents in place now before the rain really sets in. Once slugs and snails are above ground, it’s open season on your garden!
Slug and snail deterrents
