The nematode you need depends on which pest is actually causing the damage, not on how big the patch is or how worried you are about it. Each product in this range targets one insect and one insect only. Work out what is actually attacking the site first, then match it to the right pack.

Work out which pest you are actually seeing

Chafer grubs live under the turf and eat grass roots from below. The giveaway is usually birds or foxes tearing up loose turf to get at them, alongside patches that lift away like a badly fitted carpet. Leatherjackets, the larvae of crane flies, cause similar dead patches on lawns, sports turf and amenity grassland, usually showing up from late summer into autumn, but without as much digging damage from birds. Vine weevil larvae live in soil and containers rather than open turf, chewing roots until a plant wilts for no obvious reason, which makes this one for pots, borders and container-grown stock rather than a whole lawn. Ants are the easy one to diagnose: you can see the nests, often in a lawn, a cricket square or a planting border.

Buying the wrong nematode does not fail loudly. It just does nothing, because each species only infects its one host insect.

Timing and soil temperature matter more than the calendar

Leatherjacket control has two windows built into the pest’s life cycle. Apply Nemasys Leatherjacket Killer from early August to the end of October for the best result, one pack per 500 square metres, while the larvae are still small. A second window in March and April will still work, but needs one pack per 250 square metres for a weaker result, since the larvae are bigger and harder to kill by then. Soil temperature needs to be at least 12C at the time of application, whichever window you use.

Nemasys No Ants has its own rule: do not order or apply until the soil is 10C or warmer and ants are actively present in the nest, or the treatment has nothing to work on. Chafer grub and vine weevil nematodes are not given a specific soil temperature figure on the product information, but they are still living organisms, so apply when soil conditions suit nematode activity and check the product page for current guidance before ordering.

Which product for which job

Nemasys Chafer Grub Killer (500 m²) uses Heterorhabditis bacteriophora nematodes against chafer beetle larvae, one pack per 500 square metres. It arrives live, so keep it refrigerated and use it within 3 to 4 weeks of delivery.

Nemasys Leatherjacket Killer (500m²) uses Steinernema feltiae against crane fly larvae, with the main window running from early August to the end of October. It’s a living organism rather than a chemical, so treated turf is fine for children and pets once it’s been watered in.

Nemasys Vine Weevil Killer uses Steinernema kraussei and is aimed at containers, borders and open ground rather than turf, including edible crops where standard chemical treatments are often not an option. One pack treats 100 square metres, applied either as a spot treatment with a watering can or through a feeder for larger areas, and it protects the treated ground for up to 6 weeks with no residual chemicals left to manage on site.

Nemasys No Ants works differently from the other three: it doesn’t kill anything. Instead it persuades the colony to relocate away from the treated ground, which is the point if you want ants off a cricket square or a lawn without putting anything toxic into the soil. No chemicals means people and pets can use the area again straight away. Reapply every 4 weeks if the same nest comes back.

If you are still not sure which pest is behind the damage, dig into the affected area and look for grubs, larvae or nest activity before ordering. Pricing and pack availability for all four products are confirmed through the enquiry form on each product page, and the team can help match the right one to what you are actually seeing on site.

Frequently asked questions

How do I check which pest I've actually got before ordering?

Dig into a small section of the affected area. Chafer grubs and leatherjackets are both visible in the soil once you turn the turf over, vine weevil larvae show up around plant roots in pots and borders, and ants are visible at the nest entrance. If you're still not sure, get in touch with a description of what you're seeing before ordering, so you don't end up with the wrong nematode.

Can I treat more than one pest in the same lawn?

Yes, but treat each pest with its own product and its own timing rather than assuming one application covers both. A lawn with both leatherjackets and ants, for example, needs the leatherjacket treatment applied in its own window, and the ant treatment applied separately once soil temperature and nest activity allow.

Why isn't there a price shown, and how do I order?

Nematodes are living organisms, so pricing depends on pack size and delivery timing rather than being a fixed online figure. Each product page carries an enquiry form. Fill it in with your site details and the team will confirm the right pack and delivery window.