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Pest Control & Management

Lawn Treatment

Lawn Treatment

Nematodes for the treatment of
Leatherjackets and Chafer Grubs

Recent legislation has meant changes in the way we treat certain lawn pests. In particular, Leatherjackets (the larvae of the Crane fly, otherwise known as Daddy Longlegs) and Chafer Grubs (the larvae of the Chafer Beetle, also known as the May bug). We have now moved to a totally biological (organic) control, known as Nematodes, which are applied at the optimum time of year, when the young larvae or grubs are infesting the lawn.


Nematodes, which are bacteria carrying microscopic worms, can be effectively applied once evidence of Leatherjackets or Chafer Grubs has become apparent. This will serve to reduce their population and, therefore, damage to your lawn. However, they are best administered proactively as a kind of insurance policy. If you live in an area prone to such pests and/or have experienced their effects previously, your local GreenThumb branch will be in touch to advise when the best time is to have the treatment. Whilst this is generally at set times every year, the weather can have a significant influence of when, precisely, the treatment will be at its most effective.

Lawn damaged by pests

We have always viewed looking after customers’ lawns as a partnership, so it helps us tremendously if you are vigilant in looking out for signs of these pests, which are as follows:

Crane flies are generally on the wing from August to September; you will also notice the Leatherjackets (grub pictured below) coming up out of the lawn. Quite simply, the higher the number of Leatherjackets visible on the surface of the lawn, the larger the infestation.

Chafer Grubs (see picture below) are usually at their most active from mid-July to October although, dependent on weather conditions, this period could be even longer. Signs to look out for are areas within the lawn that are not looking green and appear to be somewhat stressed. The reality is that there can be a number of reasons for these conditions but if Chafer Grubs are present, pulling at the lawn will result in it lifting easily from the soil. As you continue to tug at the grass it will lift and split. Underneath, if you see grubs near the surface, this most likely means that you have an infestation and need a Nematode treatment.

If any of the above signs of infestation are appearing in your lawn, do not hesitate to contact your local GreenThumb branch. They will come out to have a look at your lawn and assess whether either of these pests is present, whether a Nematode treatment is appropriate and the most professional method to ensure you continue to experience the lush, green, weed-free lawn you desire. For example, during dry periods it is vital that the lawns are watered before this treatment is carried out. This will help to give Nematodes the best chance of success.

For any further questions, please call our lawn experts on 0800 0111 222.