Sluggish year for slugs as experts predict fewer numbers this spring

After a bumper year for the slimy molluscs in 2024, the charity’s entomology team said the cold snaps over winter and the recent dry spell mean numbers will be limited.

This will be good news for gardeners who are raising plants such as carrots, lettuce and broccoli from seed, the experts said.

The sluggish prediction contrasts with 2024, when mild wet weather across winter spring and summer led to the highest number of calls to the RHS since records began in the 1970s.

The lack of any prolonged warm dry spells over the winter months meant slugs were not forced back underground to avoid sunshine and heat, which can dry them out.

But weather aside, the RHS said its records show that years of high slug activity are often proceeded by lesser activity.

This is because of predators, disease, parasites and increased competition for food and breeding when numbers are up.

The RHS said slugs are part of a healthy garden ecosystem, with just nine of the estimated 44 UK species being notable plant nibblers.

But the charity still advises that young plants are left to grow strong indoors, under glass or high up, before being planted in beds and borders.

It also said that glasshouse thrips and red spider mites have been thriving in gardens during recent warm summers and are on the rise nationally, but the colder start to the year could delay their presence, limiting damage to bay trees, viburnum and tomatoes this year.

Hayley Jones, principal entomologist at the RHS, said: “Slugs are here to stay so learning to think like one is how you can best limit their pesky behaviour on your plot.

“While inviting wildlife into your garden will help to keep them in check you can apply layers of management that include tweaking your watering regime, using a dry textured mulch, or manually moving slugs to a compost heap after dusk.”

Gardeners blamed last year’s “abysmal” pumpkin harvest on high slug numbers thanks to dreary weather.

September’s cold and wet weather meant many plants stopped growing and needed harvesting early, with its gardeners reporting reduced squash and pumpkin crops ahead of Halloween.

Among the worst affected was Kingston Lacy in Dorset, where pumpkins and squashes had to be harvested a month earlier than usual, marking the earliest ever harvest for the property.

Many horticulturalists recommend traps rather than pellets. Upside down hollowed out oranges or melons are ideal, or marrow skins where they will hide during the day. Upside-down bin lids on top of bare soil can also work. The slugs can then be moved to somewhere well away from the garden.

Beer traps are also effective, as are commercially available nematodes, which can be watered around plants that will infect slugs and snails with parasites, which will eventually kill them.