A sluggish winter

Poke around in the nooks and crannies of your garden and you'll find life even in the depths of winter, as our volunteer and guest blogger, David Merry, demonstrates.

It hasn’t just been the birds bringing life to a drab winter garden. Winter doesn’t seem to have arrived properly this year, with hoglets and adult hedgehogs coming into the garden right through the early winter months. And out of sight, life goes on for small creatures sluggishly waiting beneath untended corners of the compost heap, the wood pile or the place you stack your plant pots.

Tidying away my own plant pots and tubs, I came upon these guests in their winter residence. Some spiders can overwinter by weaving their webs in a sheltered place. In fact, a large spider in my outside meter box is thriving with many insects its web. I’d found a number of husks at the bottom this box, and thought at first they were dead spiders. I hadn’t realised that spiders grow a new, larger cuticle exoskeleton before shedding their old one, and these were the husks I was seeing. A spider moults throughout its life.

Spiders, slugs and snails sheltering in an old garden plant pot — Spiders, slugs and snails shelter in old plant pots. Image by David Merry

Slugs and snails are busy on summer nights tormenting gardeners, but where do they go in winter?

A slugs overwintering strategy is to find hiding places that are insulated from frosts below freezing. I find them under my plant pots, shed and patio. Both adult and young slugs of most species can endure cold conditions for short periods. The eggs of slugs and snails can survive the winter in the ground until the warmth of spring, when moisture allows them to hatch.

I have only just discovered that both slugs and snails have teeth! Slugs put sharks to shame with more than 27,000 teeth arranged on their ribbon-like tongues. The tongue acts like a saw to cut through vegetation.

There are 120 species of snails in the UK, hibernating from October to April. Like slugs they need moist conditions to thrive.

A snail sliding over the wooden handle of a spade in a garden — Snail by Tom Marshall

There are 40 species of slug in Britain and they aren’t all garden pests. Most slugs prefer eating the dead detritus of living plants, which when recycled will fertilise the soil. Some like the leopard slug, Limax maximus, are carnivorous, and will eat other slugs and snails. Leopard slugs also eat fungi and rotting plants. They are common and widespread across the UK.

What many people don’t realise is that both snails and slugs are territorial. Slugs aggressively defend their food resources from intruders, suffocating competitors with a gelatinous secretion. Snails, on the other hand, have a strong homing instinct. I used to try relocating snails over the garden fence but as a plan this utterly failed and I’d be outnumbered by new and returning snails. If you try relocating snails, it must more than 20 metres from your garden.

Brown form of the great black slug making its way across a garden path — Great black slug by Nick Upton/2020VISION

Slugs and snails are useful recyclers of rotting vegetation and distribute nutrients throughout the food chain. Any garden with a good supply of food will have many hundreds of slugs and snails per square metre, with slugs laying around 200 eggs and snails laying 100 eggs per square metre in a year. The common garden snail, Cornu aspersum, can lay 80 pearly white eggs per clutch. It has six clutches per year, so that’s well over 400 eggs! This represents a rich source of food for wildlife in your garden such as birds, beetles, frogs and toads.

I don’t use pellets, sprays or beer traps in the garden. Slug and snail control is for the wonderful wildlife that lives and feeds in my precious outdoor space.