Winterising your garden: protecting against pests now for a healthier spring

As temperatures drop and plants enter dormancy, it’s tempting to hang up the gardening gloves until spring. But winter is one of the most important times to act if you want to protect your garden from damaging pests like slugs, vine weevils and other soil-dwelling insects that will otherwise emerge in force next year.

By winterising your garden now and making use of natural, biological controls such as Nemasys beneficial nematodes, you can prevent overwintering pests from wreaking havoc when the weather warms up.

Why winter pest protection matters

While the visible signs of pest damage slowdown in winter, many of the culprits don’t disappear - they simply go underground. Slugs, vine weevil larvae, and leatherjackets all spend the colder months in the soil or around plant roots, quietly feeding and preparing to resurface in spring.

Unchecked, these pests can cause serious damage to lawns, beds and borders:

• Vine weevil larvae feed on plant roots, often killing container plants outright.
• Leatherjackets weaken lawns by eating grass roots, leading to yellowing patches and encouraging birds and mammals to dig up turf in search of an easy meal.
• Slugs lay eggs that hatch in early spring, producing an army of hungry young slugs ready to devastate new shoots and seedlings.

Addressing these problems before winter sets in can dramatically reduce pest pressure in the following season.

Harnessing nature: Nemasys beneficial nematodes

One of the most effective and environmentally friendly ways to protect against these soil-dwelling pests is by using Nemasys beneficial nematodes - microscopic worms that naturally occur in healthy soil ecosystems. These organisms actively seek out and target pest larvae, entering their bodies and releasing bacteria that quickly kills the host.

Because nematodes are species-specific, they pose no threat to plants, wildlife, pets or humans - making them a trusted choice for organic gardeners and professionals alike.

Autumn and early winter applications can be particularly valuable against:

• Vine weevil larvae (using Nemasys Biological Vine Weevil Killer, which remains active down to 5°C).
• Slugs (using Nemaslug 2.0, applied before soils cool below 5°C).
• Leatherjackets (using Nemasys Biological Leatherjacket Killer).

Applying nematodes in the late autumn period – before the first series of frosts - helps to knock back overwintering populations, reducing the number of pests that survive to cause damage in spring.

Winter garden tasks to support pest prevention

In addition to nematode treatments, a few simple winter maintenance steps can make your garden less inviting to pests and disease:

1. Clear up fallen leaves and debris

Dead plant material provides cover for slugs, snails and other pests. Compost healthy debris but dispose of anything showing signs of disease.

2. Turn over the soil

Lightly cultivating soil in borders or vegetable beds exposes overwintering pests and eggs to frost and predators like birds and ground beetles.

3. Clean pots and greenhouses

Scrub containers and clean greenhouse shelves to remove pest eggs and larvae hiding in crevices.

4. Mulch wisely

Apply a protective mulch to exposed soil once pest populations have been reduced — this helps protect beneficial soil life and prevents erosion through winter weather.

5. Encourage natural predators

Birds, hedgehogs, frogs and ground beetles are valuable allies. Provide shelter, water and food sources to keep them active in your garden year-round.

The payoff in spring

By acting now, you’re investing in a healthier, more resilient garden come spring. Beneficial nematodes continue to work quietly below ground ahead of the cooler months, reducing pest numbers naturally and sustainably. Combined with good hygiene and habitat management, they form the cornerstone of an integrated, eco-friendly pest control approach that benefits both your plants and the wider garden ecosystem.

So before you pack away your tools for winter, give your garden a little extra care - your spring blooms will thank you for it.

Ends

Editors notes

Nematodes are naturally occurring microscopic worms, already present in our soil. Beneficial nematodes attack and kill targeted garden pests. They are compatible with organic farming, easy to use and can even be kept in your fridge!

Research scientists have isolated the nematodes that kill specific garden pests including Slugs, Vine weevils, Leatherjackets, Caterpillars, Codling moth and much more.

BASF’s state of the art production facility in the UK produces billions of nematodes in a form that is easily applied by gardeners. Over 20,000 different species of nematodes have been classified, although some estimates put the total figure closer to one million! BASF has the largest specialist nematode production facility in the world, growing trillions of beneficial nematodes for use in their Nemasys range of pest control products.

BASF experts are available for interviews, features and expert comment on biological pest control management, and product is available for reviews, competitions and product trials.