25 February 2026

When to use nematodes for slugs, vine weevil, leatherjackets and chafer grubs?

All our nematode controls contain naturally occurring and environmentally friendly nematodes that are easy to use, effective and are safe for children, pets, wildlife, birds and bees. As the biggest supplier of nematodes in the UK and because we have fresh deliveries of nematodes several times a week, you are guaranteed the freshest stock with the longest expiry date available. Our nematodes are dispatched DAILY by 1st class post. With nematodes available for controlling slugs, vine weevil, leatherjackets, chafer grubs, ants, box caterpillar, Sciarid and Scale BUT when should you start applying nematodes?

Controlling Slugs – Control slugs NATURALLY by applying EasyNem Slug Nematodes, which contains natural nematodes, that are effective at controlling slugs, but unlike chemical controls, are safe for children, pets, birds and wildlife. PLUS customers report fewer snails too! 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.

Controlling Vine Weevils – Control vine weevils naturally by applying Nemasys® Vine Weevil Killer, which unlike chemical controls, kills the vine weevil grubs BEFORE they attack the plants and is so safe you can use on pot plants (both in the greenhouse and conservatory), container plants outside, and anywhere in the garden. It also SAFE to use on food crops such as strawberries and herbs!  Apply Nemasys® Vine Weevil Killer as follows :-

1. Treat grubs discovered UNDERGLASS at anytime of year. Available all year round.
2. Treat grubs discovered OUTDOORS as long as the soil temp is 5c i.e. normally between March and October.
3. Discovered a heavy infestation? Order a Spring and Autumn Offer to fit 2 applications in before the end of the year and save money too!
4. Apply MORE OFTEN in warmer situations or where vine weevils are a persistent problem. Order an Extended Programme for delivery throughout the year and save money too!

Controlling Leatherjackets – Control leatherjackets naturally by treating with Leatherjacket Nematodes containing millions of natural nematodes – mix with water and apply the nematodes (Steinernema Feltiae) to the infected lawn with a watering can fitted with a Coarse Rose or a NemaCan or an EasyNem Applicator. When should Leatherjacket Nematodes be applied?

1. Apply Leatherjacket Nematodes in Sept/Oct/Nov – This is the ideal time to treat as the soil is warm PLUS the leatherjackets are newly hatched, the soil is warm (needs a daytime soil temp of 10c) and are the most susceptible to the nematodes, so if you have had leatherjackets in the past or have discovered a leatherjacket infestation or your neighbours are infested and you want to keep them at bay, treat in Sept/Oct/Nov. When applying in the autumn, each 50m Nematode pack will treat 100 sqm. Pre-order for delivery in the autumn.
2. Apply Leatherjacket Nematodes when leatherjackets are discovered – Leatherjacket Nematodes are normally applied in September as this is when the leatherjackets are newly hatched and most susceptible to the nematodes, but if you have discover leatherjackets (not daddy long legs) at any other time of year i.e. in the spring/summer then treat at double strength as the mature leatherjackets are much harder to kill, but you must treat in September as well. When applying in the spring / summer at double strength, each pack will treat 50 sqm. Available ALL YEAR ROUND.

Controlling Chafer Grubs – Control chafer grubs naturally by applying Green Gardener Chafer Grub Killer containing millions of nematodes (Heterorhabditis bacteriophora) to the infected lawn as soon as the chafer grubs are discovered and the soil temp must be 12°C or apply in the autumn (Sept / Oct) as this is when the chafer grubs are the most susceptible to the nematodes. Apply Chafer Grub Nematodes as follows :-

• Apply Green Gardener Chafer Grub Killer in September/October – This is the ideal time to treat as the soil is warm PLUS the chafer grubs are newly hatched and are the most susceptible to the nematodes, so if you have had chafer grubs in the past or have discovered a infestation or your neighbours are infested and you want to keep them at bay, treat in September/October. Pre-order for delivery in the Autumn.
• Apply Green Gardener Chafer Grub Killer when chafer grubs are discovered – Chafer Grub Killer is normally applied in September as this is when the chafer grubs are newly hatched and most susceptible to the nematodes, but if you have discover chafer grubs at any other time of year i.e. in the spring/summer then you can treat during the year (and the soil temp is 12°c), but you must treat in September as well. Available from mid-March onwards.

Available to buy now