What are leatherjackets?

Leatherjackets are the hatched larvae of crane flies and can unfortunately wreak havoc on your lawn. Crane flies or daddy long legs as they are sometimes known, lay their eggs on your lawns surface between August and October. These eggs will then lay dormant on your lawn for months until they get the ideal conditions to hatch in. Wet, boggy conditions cause the eggs to hatch which is why we are more likely to see their damage take place during late summer and early autumn.

Signs you have leatherjackets

As said, you are more likely to see leatherjackets in your lawn between August and October, but any extreme or very wet conditions may cause older eggs to hatch. The first sign you will notice is birds like crows or magpies pecking at your lawn in search of a sneaky treat. If they are focusing on a particular area, you may want to lift the turf to see if there are leatherjackets beneath.

The second sign is random patches of yellow in your lawn – that may seem to get bigger as time goes on. This is because the leatherjackets are eating the roots of your grass, which causes them to die off and turn yellow. Again, the easiest way to check if you have leatherjackets is to lift some of the turf where the yellow patches are appearing. If there is a collection of brown grubs in the soil looking rather suspect, unfortunately you have leatherjackets!

How to get rid of leatherjackets

The only way to remove leatherjackets from your lawn is to use nematodes. Nematodes are tiny, microscopic bacterial worms that enter the leatherjacket and subsequently poison it.  You can purchase nematodes for a range of garden pests, but to make sure you have the right product, look specifically for the Steinernema feltiae nematode. Always read the instructions for use.

How to prevent leatherjackets

Unfortunately, you can’t prevent crane flies from laying their eggs on your lawn and you also can’t prevent our very wet and rainy UK weather! The best course of action for prevention is to make sure that when rain does come, that your lawn easily drains and does not encourage water to stick around. Whilst this can be helped by installing drainage, it is also a good idea to ensure that your lawn is as level as it can be with no dips, and that your soil is not compact. Aeration is a great way to keep your soil from becoming compact and to help aid drainage. Likewise, you should aim to keep your lawn healthy so that when it does bounce back from any leatherjacket damage, the rest of your lawn is in good condition.

Once there is no remaining leatherjackets, you will need to remove the damaged grass and seed these areas. For more advice on how to repair leatherjacket damage, see our blog here.