Leatherjackets & Chafer Grubs in Lawns (UK Guide)

If your lawn is suddenly patchy, lifting easily, or being torn apart by birds, you may have a leatherjacket or chafer grub infestation.

These lawn pests feed on grass roots beneath the surface and can destroy large areas quickly if left untreated.

Here’s how to identify them, treat them properly, and repair the damage.

What Are Leatherjackets?

Leatherjackets are the larvae of crane flies (often called “daddy long legs”).

They live beneath the soil surface and feed on grass roots, weakening the lawn from underneath.

A small population is increasingly common in UK lawns and may not require treatment.

But a large infestation can:

• Kill patches of grass

• Cause turf to lift like carpet

• Prevent successful reseeding

• Attract birds and wildlife that rip up your lawn

What Are Chafer Grubs?

Chafer grubs are the larvae of chafer beetles.

Like leatherjackets, they:

• Feed on grass roots

• Live underground

• Cause turf dieback

• Attract birds

They are visually different:

• Creamy white body

• Light brown head

• Curved shape

• Two visible pairs of front legs

Crows and other birds often dig them up as a food source.

What’s the Difference Between Leatherjackets and Chafer Grubs?

Both cause root damage but treatment timing varies slightly.

Signs You Have an Infestation

Look out for:

✔ Dead or thinning patches
✔ Grass that lifts easily from the soil
✔ Increased bird activity (pecking, tearing)
✔ Large numbers of crane flies in late summer
✔ Visible grubs in the top layer of soil

If turf lifts like loose carpet, roots may already be heavily damaged.

When Should You Treat Leatherjackets or Chafer Grubs?

Timing is critical.

The most effective treatment window is when larvae are young and small.

For most UK lawns, that means:

• Late summer to early autumn (July–October)

Treating in spring is often less effective because larvae are larger and more resistant.

Important:
Do not reseed until the infestation is under control. Otherwise, new grass roots will simply be eaten.

How to Get Rid of Leatherjackets & Chafer Grubs

1️⃣ Nematode Treatment (Recommended)

Biological nematodes are the most reliable solution in the UK.

They:

• Target larvae specifically

• Are safe for pets and wildlife

• Work best when soil is warm and moist

Apply during the recommended treatment window and keep soil damp for 2–3 weeks after application.

You should wait several weeks before overseeding.

2️⃣ Black Plastic Method (Short-Term Option)

Some lawn owners use the “black sheet method”:

1. Water lawn heavily

2. Cover with black plastic overnight

3. Grubs surface due to lack of oxygen

4. Rake up in the morning

This can reduce numbers but is generally less effective for chafer grubs and does not fully eliminate infestations.

Life Cycle of Leatherjackets

Understanding timing helps with prevention.

The cycle:

1. Adult crane flies lay eggs (late summer)

2. Eggs hatch into larvae

3. Larvae feed through autumn and winter

4. Pupate in spring

5. Adults emerge

The key treatment window is early larval stage.

Repairing Lawn Damage After an Infestation

Once the pests are controlled, renovation is essential.

Damaged roots mean:

• Weak grass recovery

• Patchy regrowth

• Soil gaps inviting weeds

To restore the lawn:

1. Rake out dead material

2. Lightly aerate

3. Overseed

4. Apply appropriate seasonal fertiliser

If more than 30–40% of the lawn is damaged, a larger renovation may be required.

How to Prevent Future Infestations

Healthy lawns are more resilient.

While pests can still lay eggs, a thick, well-fed lawn:

• Recovers faster

• Competes better

• Shows less visible damage

Seasonal feeding strengthens root systems, making turf more tolerant of stress and recovery faster after attack.

What Should You Use to Repair the Lawn?

For damaged lawns:

• The Lawn Pack - ideal for established lawns needing recovery

• The Lawn Pack Plus (double seed) - suitable where coverage is below 50%

Applied correctly, you can see visible thickening and colour improvement within 4 weeks.

Final Thoughts

Leatherjackets and chafer grubs can feel devastating but they’re manageable with the right timing and approach.

Control the infestation first.
Then renovate properly.
Then strengthen your lawn to prevent future issues.

If you’re unsure which pest you’re dealing with, send us a photo, we’re happy to help.

Stay green 🌱
The Lawn Pack Team