How to Control Leatherjackets in Your Lawn

I get asked this a lot by clients around Cheltenham, especially when lawns suddenly thin out with no obvious cause. One common culprit is leatherjackets, the larvae of crane flies (daddy longlegs).

What are leatherjackets?

Leatherjackets are greyish-brown grubs that live in the soil and feed on grass roots. You’ll often notice patches of weak, yellowing grass or areas that lift easily like a carpet due to root damage.

How do you know if you’ve got them?

• Patches of thinning or dying grass, often worsening in spring.

• Increased bird activity (particularly starlings, crows, or magpies pecking at the lawn).

• Seeing crane flies in late summer or autumn, when they lay their eggs on the lawn.

If you peel back a small section of turf and find these grubs, they’re likely leatherjackets.

When do they cause the most damage?

Leatherjackets hatch in autumn and feed on grass roots through winter and spring. Damage is usually most visible from March to May as they grow larger before pupating into crane flies.

How can you control leatherjackets?

1. Encourage birds. Natural predators like starlings will feed on leatherjackets, though they can cause some lawn disturbance in the process.

2. Nematode treatment. Applying nematodes (microscopic worms) is the most effective, environmentally friendly method. They infect and kill leatherjackets in the soil. The best time for nematode application is late August to early October, when the larvae are small and most vulnerable.

3. Good lawn care. A strong, healthy lawn is more resilient. Regular feeding, aeration, and overseeding will help the grass recover if damage occurs.

Professional help with leatherjacket control

If your lawn is suffering from leatherjackets, I can assess the extent of damage and recommend a treatment plan, including nematode applications and recovery feeding to strengthen the lawn again.

Noticed thinning patches and birds pecking at your lawn? Message me if you’re concerned about leatherjackets and would like a professional assessment and treatment.

Happy Gardening