Pests

A healthy lawn can be affected by a variety of pests, from moles tunnelling beneath the surface to grubs feeding on grass roots. Recognising the signs early and knowing how to manage these issues can help you protect your lawn and keep it lush, green, and pest-free.

Mole in lawn

Moles

Signs: Raised ridges and soil heaps (molehills) appearing overnight.

Causes: Moles tunnel through lawns searching for insects and worms. They don’t eat the grass but can disturb roots and create uneven ground.

Treatment:

  • Remove molehills and flatten tunnels before reseeding affected areas.

  • Encourage moles to move on using humane deterrents such as sonic devices or natural repellents.

  • Once activity stops, repair damaged areas with Johnsons Quick Fix Lawn Seed for fast regrowth.

Mole in lawn

Leatherjackets (Crane Fly Larvae)

Signs: Yellowing grass, spongy patches, or bare spots where grass lifts easily from the soil. Birds such as starlings or crows may peck at the lawn to feed on the grubs.

Causes: Leatherjackets feed on grass roots, most commonly in late summer and autumn after crane flies lay their eggs.

Treatment:

  • Rake or spike the surface to expose larvae to predators and dry conditions.

  • Apply a biological nematode treatment in late summer or autumn when soil temperatures are warm.

  • Once the infestation is under control, overseed thin or bare areas to promote healthy recovery.

Chafer Grub in lawn

Chafer Grubs

Signs: Patches of loose turf that can be peeled back easily, often with white C-shaped grubs visible underneath. Birds and badgers may dig up areas in search of them.

Causes: Chafer beetle larvae feed on roots, weakening the lawn. Damage is usually seen in late summer and early autumn.

Treatment:

  • Apply nematodes specific to chafer grubs between July and September.

  • Avoid overwatering, as damp soil encourages egg-laying.

  • Lightly rake, re-level, and reseed damaged sections with a resilient lawn seed mix such as Johnsons Tuffgrass once the pests have gone.

Ant hill in Lawn

Ants

Signs: Small mounds of loose soil on the lawn surface, especially in dry, sunny spots. Grass may become uneven where nests disturb the soil.

Causes: Ants build colonies in dry, sandy soil. Their tunnels loosen the ground, and soil mounds can smother grass blades, leaving patches bare.

Treatment:

  • Brush away soil mounds before mowing to avoid damaging your blades.

  • Water the area regularly — ants prefer dry conditions, so moisture discourages them.

  • If colonies are extensive, apply an ant control treatment suitable for lawns, we recommend the Neudorff AntFree Ant Killer Granules

  • Once the nests are inactive, re-level and overseed to restore grass cover.

Note: Ants rarely cause long-term damage. Keeping your lawn dense and well-watered is usually enough to deter them naturally.

Bee Hive in lawn

Bees (Mining & Solitary Bees)

Signs: Small holes or low soil mounds scattered across dry, sandy areas of lawn in spring or early summer.

Causes: Solitary bees burrow into dry soil to create nesting chambers. They do not form hives or cause widespread lawn damage, and are active for only a few weeks each year.

Treatment:

  • Do not use pesticides — bees are essential pollinators and protected in the UK.

  • Lightly water or rake over affected areas after the bees have moved on to encourage grass recovery.

  • If activity is in high-traffic zones, consider reseeding a less-used section of your lawn to attract them there instead.

Note: Solitary bees are harmless and beneficial. It’s best to let them complete their short nesting cycle before repairing your lawn.

Earth Worm in lawn

Worms

Signs: Small worm casts (tiny piles of fine soil) appearing on the surface, especially in damp weather.

Causes: Worms naturally aerate the soil and improve nutrient cycling - both signs of healthy soil. Casts appear as a byproduct of their feeding and tunnelling activity.

Treatment:

  • Allow worm casts to dry, then brush or lightly rake them back into the grass.

  • Avoid using chemical treatments — worms are vital for lawn and soil health.

  • Reduce compaction with aeration and avoid overwatering, which can encourage excessive casting.

Note: Regular brushing and good lawn care practices will minimise the visual impact of worm casts without harming these beneficial creatures.

How to Repair Damaged Areas

Step 1: Rinse the area promptly

If you spot your dog using the lawn, give the area a good soaking with a watering can or hose to dilute the nitrogen before it can cause damage.

Step 2: Remove dead grass

Rake out any brown, straw-like patches to allow new growth to take hold.

Step 3: Reseed with a hardwearing mix

Use a resilient lawn seed, such as Johnsons Tuffgrass with Dog Patch Resistance, which contains specially selected grass varieties tolerant to dog urine. Lightly rake in the seed, water regularly, and keep traffic off until it’s established.

Step 4: Feed and maintain

Once new growth appears, feed the area with a balanced lawn fertiliser to encourage strong, even recovery.

How to Prevent Future Damage

Encourage Hydration

Make sure your dog always has access to fresh water. Well-hydrated dogs produce less concentrated urine.

Regular Watering

During dry spells, water your lawn regularly to help flush out built-up salts contained within dog urine.

Designate a Toilet Area

Although not always the easiest solution, training your pet to use one specific area of your garden, ideally with gravel or mulch for toileting, can be the best option for protecting your lawn.

There are great training resources on the RSPCA website.

Overseed Each Season

Consider overseeding with a hardwearing or pet-resistant lawn seed, such as Johnsons Tuffgrass with Dog Patch Resistance, which contains specially selected grass varieties tolerant to dog urine. This should be done each sprint and autumn to maintain lawn density and resilience.

Stay Consistent With Your Lawn Care

Regular mowing, aeration, and feeding will help your grass recover faster from any damage.

Don’t Let Dog Urine Ruin Your Lawn

Repair and Protect It with Tuff Grass