13 February 2026

How to control slugs using slug nematodes

Slugs are one of the commonest pests of garden plants attacking the foliage of herbaceous, particularly hostas and delphiniums, bedding and vegetable plants. Some species also feed on plant roots. They can also be a problem under-glass and in cold frames at the start of the season, with young seedlings being particularly vulnerable to attack.

ABOUT SLUGS

What do slugs do to the plant?

Slugs feed on the foliage, flowers, stems & roots. They leave ragged holes in mature leaves or they can destroy young plants & ruin the appearance of larger plants such as hostas. Some slugs feed on the roots of plants and do not appear on the surface.

What do they look like?

Slugs come in all shapes, sizes & colours, but they do have several things in common. Covered in a watery mucous and requiring water for reproduction, so they all like damp conditions. They tend to be most numerous and do the most damage in warm, damp springs and autumns. Many are nocturnal and hide during the day under stones or leaf litter. They leave a characteristic ‘slime trail’ on the soil/leaf surface helping to identify the pest.

What is the slugs life cycle?

Slugs can breed throughout the year except in periods of drought or frost. Peak egg laying is in the autumn and spring. The eggs, translucent and round, are laid in clusters in damp soil and rotting vegetation, where they are protected from frost and drought. Some species lay eggs well below the soil surface. In warm weather they may hatch in a few weeks, but those laid in autumn/winter tend to hatch in the spring.

Control slugs naturally by applying Slug Nematodes.

Nematodes are microscopic worms that are found naturally in the soil and are just about invisible to the naked eye. They are already there in small numbers, but by applying extra you can boost their numbers and make them more effective at controlling pests. A wide range of nematode species exist naturally in your soil, where they feed on organic matter. By adding extra Phasmarhabditis Californica nematodes in large numbers to the soil or compost under the correct conditions, slugs are killed without affecting other beneficial soil organisms. The nematodes enter the slug through the slug ‘mantle’ (the saddle-like structure on it’s back). They carry with them a slug destroying bacterium, which is effective at a soil temp. of 5C+. The nematodes and bacteria multiply and within days the slug will stop feeding and burrow underground to die out of sight. Both our EasyNem Slug Nematodes and Nemaslug Slug Killer contains MILLONS of the natural beneficial nematodes.

What are the advantages of using Slug Nematodes?

The nematodes contained in EasyNem Slug Nematodes and Nemaslug Slug Killer are approved for use in organic gardens and are approved by the Soil Association. They contain millions of natural nematodes, which are effective at controlling slugs and unlike chemical controls, are safe for children, pets, birds and wildlife – song birds i.e. thrushes, hedgehogs, frogs, toads and some insects i.e. ground beetles love to feed on slugs and their eggs, so it is important not to affect them. These predators have a significant impact on the slug population, but many of the chemicals used in slug pellets can be toxic to this wildlife. There are also increasing concerns about the effects of these chemicals on pets. Unlike nematodes slug pellets do NOT work well during wet weather – exactly when you need protection against slugs. EasyNem Slug Nematodes and Nemaslug Slug Killer kills slugs BOTH above and below ground.

How are Slug Nematodes supplied?

The microscopic nematodes are supplied as a harmless powder. This nematode powder is perishable and needs to be kept in a fridge, so you won’t find it on a garden centre shelf – it needs to be sent fresh by mail order. The pack has an expiry date (usually about 2 weeks) and must be kept in a fridge until applied. This is a perishable product and should be used in 1 application before the expiry date. Use all the powder in one go and once the powder has been mixed the solution should be used immediately. The powder is in sealed packs and is totally harmless to your yoghurts and cheese!

When should slug nematodes be applied?

1. In the Spring AS SOON as the soil temperature reaches 5ºC (normally mid March to tackle the young slugs before they start breeding. The nematodes will survive below this temperature, so don’t worry if temperatures drop at night early in the season, as the nematodes start to work again as soon as the temperature rises.
2. Each application controls slug for 6 weeks (during this time the nematode level returns to normal), so to keep slugs at bay re-apply at 6 weekly intervals. Or Planned Programmes are ideal for automatically delivering packs at 6 weekly intervals.
3. In the Autumn BEFORE the temp drops (normally early October), as the fewer slugs there are to over-winter and breed, the less slugs there will be next spring.

You can also choose to apply at specific times of the year to protect your crops when they are at their most vulnerable :-

• Apply to herbaceous plants in the spring as soon as the new growth starts. Repeat 6 weeks later for particularly susceptible plants such as hostas.
• Apply to vegetables plants Immediately after planting brassicas, runner beans, courgettes etc.
• Apply once seeds are sown. Apply immediately after sowing to protect the young seedlings as they emerge from the soil.
• Potatoes should be treated after the first earthing up.
• Treat bedding plants immediately after planting.

How are slug nematodes applied?

The nematodes are supplied as a harmless powder, which is mixed with water and applied by watering can through a coarse rose (specific NemaCan available or fit a Coarse Rose to an existing can) or for larger areas use a EasyNem Hose-end Applicator. As the slugs crawl across the soil, or even under it to eat your favourite plant, the nematodes enter the slug. Nematodes should only be applied to moist soil (not hard surfaces or lawns). Bark or gravel mulches will need to be removed before application and then replaced.

Will chemicals affect the slug nematodes?

Normal spraying of the aerial parts of the plant to control greenfly etc. will have no effect on the nematodes, which live in the soil. Fertilisers and weedkillers will not affect the nematodes either.

Are these nematodes dangerous?

Only if you are a slug! They only attack slugs and are harmless to you, your children, pets and other wildlife. Slugs normally crawl underground and will expire gracefully there. Slugs are an important source of food for a number of birds – even if a bird eats a slug controlled by Nemaslug® the bird will not be affected!

What about snails?

Slug Nematodes have been shown to give control to young snails and repel older ones, so it will help to reduce snail populations as well

How are Slug Nematodes despatched?

Nematodes will be despatched by Royal Mail TRACKED 1st class post and normally arrive next day. You can also request a future dispatch date when ordering if you need to time your application for a specific time of year. They are packed in a padded envelope and will fit through the letterbox.

Buying Slug Nematodes? We have 2 different Slug Nematodes : –

EasyNem Slug Nematodes are our own brand of slug nematodes. Containing 15 million, natural, beneficial nematodes (Phasmarhabditis Californica), this pack contains MORE slug killing nematodes than other brands, our NEW “green” EASYMIX formulae is easier to mix and apply and each pack treats 25% more area with each pack treating up to 50 sqm. Buy a 50 sqm pack of EasyNem Slug Nematodes for £14.99 or as part of a planned programme.

Nemaslug Slug Killer – Available in 2 different pack sizes. The standard 40 sqm pack of Nemaslug contains 12 million Phasmarhabditis Californica nematodes, while the larger pack contains 30 million nematodes and treats up to 100 sqm. Buy a 40 sqm pack of Nemaslug for £16.99 or a 100sqm pack of Nemaslug for £31.99.

EasyNem Slug Nematode Programmes – Each pack control slugs for six weeks once applied, so for the best results re-apply it regularly every 6 weeks throughout the growing season. It is a perishable product, so our unique planned programmes are designed to make your life easier and keep your garden slug free, by automatically topping you up with with fresh packs of Slug Nematodes every 6 weeks PLUS save money too! We offer 2, 3, 4, 5 and 6 pack programmes, so choose your programme and we will send that number of 50 sqm packs at 6 weekly intervals.

Available to buy now