Leatherjackets in Lawns

Leatherjackets

Leatherjackets, the larval stage of crane flies (daddy long legs), the larvae hatch in late summer or early autumn and spend several months in the soil, feeding on the roots of grasses and plants. They are also particularly active in spring when the weather warms up.

The damage caused by leatherjackets can be significant, with the larvae chewing through grass roots and causing large, brown patches on lawns. Birds, particularly crows and starlings, often dig up the turf to feast on the larvae, further damaging the lawn.

By springtime, the damage is clear, bare patches, discoloured grass, and weak areas where the grass has struggled to establish itself due to root damage. The leatherjacket infestation can also leave your lawn vulnerable to further pest attacks and disease.

What Are Leatherjacket Nematodes?

Leatherjacket nematodes are microscopic worms which kill the larvae. These nematodes are naturally occurring in the soil, and using them in your garden you are just topping up what is already there.

When introduced into the soil, leatherjacket nematodes seek out and infect the larvae of the leatherjacket. The nematodes enter the larvae’s body, where they release bacteria that kill the pest within 48 hours.

This natural predation process helps control leatherjackets without the use of harmful chemicals or pesticides, making it an ideal solution for organic and eco-conscious gardeners.

Why Use Leatherjacket Nematodes Instead of Chemicals

Nematodes are naturally occurring and pose no harm to beneficial insects, animals, or humans.

Unlike chemical pesticides, leatherjacket nematodes do not leave harmful residues in the soil. They work in harmony with the ecosystem.

Leatherjacket nematodes are easy to use. Simply dilute the nematodes in water and apply them to the affected areas using a watering can or sprayer. The nematodes will quickly spread throughout the soil, seeking out their target pests.

How to Use Leatherjacket Nematodes in the UK

If you’ve noticed signs of leatherjacket damage on your lawn or garden, applying nematodes is a straightforward process. Follow these steps to get the best results:

The best time to apply leatherjacket nematodes is from late spring to early autumn when the leatherjackets are actively feeding in the soil. The nematodes need moist soil to be effective, so apply them during a cool, damp day. Ideally, apply in the early morning or late afternoon when the weather is cooler.

Leatherjacket nematodes are easy to use, just mix with water. Using a nematode applicator, sprayer or watering can, distribute the nematodes evenly across the lawn. It’s important to water the soil thoroughly before and after applying the nematodes to ensure they reach the larvae.

The soil should be moist for at least a few weeks after application this helps the nematodes move around in the soil.

It may take a further applications for full control, especially in cases of severe infestations. Reapply in late summer or early autumn for the best results.