I have had to pick the grubs out of the lawn and feed them to the birds up until now! These nematodes are brilliant. Mr G from Essex.
Dear all, I applied your treatment for leather jackets in the autumn and the result, a lawn that looks like a lawn! thanks. Regards Trevor Godwin

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Green Gardener - the natural way to keep your garden looking good
Nemasys Leatherjacket Killer - Leatherjackets are the larval stage of the crane fly / daddy long legs & they can quickly devastate a lawn. They lay their eggs into the same piece of lawn each year, so an infestation can quickly escalate from a small brown patch to a full scale infesation. Birds (especially starlings) pecking at the lawn is another sure sign of an infestation.


Control Leatherjackets NATURALLY by applying Nemasys Leatherjacket Killer as soon as you discover grubs or apply when the grubs are at their most destructive i.e. in the autumn (September / October). 


"The nematodes you advised for leather jackets on the lawn last year was very effective, Thank you." K Iris Millar

Nemasys Leatherjacket Killer

Large Leatherjacket Killer treats 100 sqm - available again in 2018
Eco Leatherjacket Killer treats 500 sqm - available again in 2018
Haws Rose no.14£6.75Add Haws Rose no.14      
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Hose-end Feeder£13.50Add Hose-end Feeder      
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Nemasys® Leatherjacket Killer - Leatherjackets are the larval stage of the crane fly or daddy long legs and they can quickly devastate a lawn. Control leatherjackets naturally by treating with Nemasys® Leatherjacket Killer when they are discovered (and the soil temperature is 10c) or apply when they are at their most destructive i.e. in the spring (April) and in the Autumn (Sept/Oct).

N.B. Nemasys Leatherjacket Killer needs a soil temperature of 10c, so it is too late to apply this year. The next opportunity to treat is April 2018, so Nemasys Leatherjacket Killer will be back on sale in late March 2018.


Leatherjackets - Crane flies or daddy long legs lay their eggs in the same area of lawn from which they emerge, so numbers increase rapidly. These eggs hatch in August / Sept and the larvae immediately start to feed on the grass roots. The leatherjackets will feed though the autumn, before overwintering. They start feeding again the following spring and gorge on grass roots before pupating to emerge as adults in August. The symptoms of an attack are that grass growth slows and yellow patches appear PLUS the grass easily pulled up with little or no root growth. One of the biggest indicators of an infestation are birds, particularly starlings, which will pull at the lawn (causing even more damage) in search of the leatherjackets to eat.


Leatherjackets - In August, customers report clouds of daddy long legs emerging from lawns in early morning leaving behind the casings sticking up in the lawn (see left). As the daddy long legs emerge, they start to lay their eggs back in infected lawns starting the whole cycle again - the next generation of leatherjackets hatch within 2 weeks. Leatherjackets are up to 2.5cm / 1" long, greyish black in colour, legless and with no distinct head. Late autumn when the leatherjackets are newly hatched, close to the surface and the soil is warm is when the leatherjackets are the most susceptible to the nematodes.


Nemasys® Leatherjacket Killer - Control leatherjackets naturally by applying Nemasys® Leatherjacket Killer containing millions of nematodes (Steinernema Feltiae) to the infected lawn as soon as the leatherjackets are discovered (and the soil temperature is 10c) or when the leatherjackets are active i.e. in the autumn (Sept / Oct) and in the spring (April). Nemasys® Leatherjacket Killer is effective at killing leatherjackets, but is harmless to children, wildlife and pets and the lawn may be used immediately after application. Apply as follows :-

  • Apply Nemasys® Leatherjacket Killer in September/October - This is the ideal time to treat as the soil is warm PLUS the leatherjackets are newly hatched and are the most susceptible to the nematodes, so if you have had leatherjackets in the past or have discovered a leatherjacket infestation or your neighbours are infested and you want to keep them at bay, treat in September/October.
  • Apply Nemasys® Leatherjacket Killer when leatherjackets are discovered - Nemasys® Leatherjacket Killer is normally applied in September as this is when the leatherjackets are newly hatched and most susceptible to the nematodes, but if you have discover leatherjackets (not daddy long legs) at any other time of year i.e. in the spring/summer then treat at double strength as the mature leatherjackets are much harder to kill, but you must treat in September as well.

Nemasys® Leatherjacket Killer should be applied to a moist lawn (we recommend pre - watering) on a dull day or in the evening. After application you MUST wash the nematodes into the lawn by watering heavily with a hose or a sprinkler. To apply, simply mix the nematodes with water and apply with a watering can or hose-end feeder PLUS economy packs can also be applied with a sprayer. Once applied the nematodes will seek out the leatherjacket larvae. On contact they enter the larvae and destroy it. Having destroyed the leatherjacket ,the nematodes multiply and are released back into the soil to hunt down more leatherjackets.  Nemasys® Leatherjacket Killer is a perishable, living product, so it is sent out fresh by Royal Mail 1st class post. Being a perishable, living product, it must be used before the expiry date (which is marked on the inside of the pack and will be at least 2 weeks) and it must be stored in the fridge until it is needed. Once opened, the contents do not keep, so it must be used in one day - do NOT store the made up solution or powder. 1 to 4 packs will go through your letterbox and are fine on the doormat while you are at work. N.B. Large orders i.e. 5 or more packs will not fit through the letterbox, so someone will need to be in to receive it. For smaller lawns just make solution stronger - you can't overdose!


Nemasys® Leatherjacket Killer Large Pack - treats 100 sqm in the autumn - £21.75 - finished for this year - available again in 2018

Nemasys® Leatherjacket Killer Economy Pack  - treats 500 sqm in the autumn - £79.50 - finished for this year - available again in 2018


"Hi Jon, I keep on forgetting to drop you a line, but I wanted to tell you how good that leatherjacket treatment was. My grass is looking lush again. A bit more rain in recent weeks has helped as well but it is green with no starlings attacking it any more!" Cheers Simon

"The leatherjacket treatment which I got from you for the lawn previously was a great success - thanks!" from K Iris Millar by email


"Dear all, I applied your treatment for leather jackets in the autumn and the result, a lawn that looks like a lawn! thanks" Regards Trevor Godwin


"Hello Jon, this is just to let you know how pleased we are with the leatherjacket control. We applied the nematodes according to the instructions and the brown patches on our lawns have definitely stopped spreading. The fresh grass is already growing. We also used your autumn lawn feed and the benefit is apparent. Last year we helplessly watched as our lawns were mutilated. This year we have been able to fight back. Thank you, from two keen gardeners." Brenda and Cyril.


"Just to let you know we now have a green lawn again – so thank you!" Kind regards Philip 


"Dear Jon, I have 2 lawns but every summer they went mostly patchy yellow and looked half dead and straw like, despite using fertiliser and watering in dry spells. No one could help and then we came across your site and read about leatherjackets. I decided to try your nematodes. I admit I thought it all was a lot of nonsense!! How wrong I was. To my amazement this year both lawns are lush and beautifully green - I find it hard to believe ! Thank you for lovely grass again. I feel that your nematode treatment should be more widely known and written about by gardening column writers to say nothing of books." Many thanks again Derek Wallace

"Thanks for your speedy answer to my questions about the Leatherjacket killer. It is a great product that certainly saved my increasingly ravaged lawn, this year it looked better than it had in ages." Regards Tony


Nemasys® Leatherjacket Killer application methods Nemasys® Leatherjacket Killer is easy to use. Simply mix the harmless powder with water & apply directly to the lawn with a watering can fitted with a rose or a hose-end feeder PLUS Economy packs can be applied with a sprayer. Use the whole pack before the expiry date, which is marked on the inside of the pack and will be at least a couple of weeks.

Haws Rose no.14 Rose - Watering cans need to be fitted with a coarse rose to allow the nematodes to flow freely. We recommend using the Haws Rose no.14, as not all roses are suitable.


Hose-end feeder - Used for applying nematodes to large areas i.e. ideal for applying economy packs to large lawns. This feeder can also be used for applying liquid feed to plants and lawns. Attaches via standard hose-pipe connector and features both a rose head and jet spray as well as an on / off switch for water flow.

Lawn Pest Pack

Lawn Pest Pack treats 100 sqm - despatched ASAP
Eco Lawn Pest Pack treats 500 sqm - currently unavailable

Lawn Pest Pack - Many people struggle to identify, which pest their lawn has i.e. either leatherjackets or chafer grubs. If in doubt, you can treat with BOTH Nemasys Leatherjacket Killer AND Nemasys Chafer Grubs Killer at the SAME TIME. Control leatherjackets and chafer grubs by treating when they are at their most destructive i.e. in the Autumn. 


Lawn Pest Pack - The symptoms of a Chafer Grub and Leatherjacket attacks are very similar i.e. grass growth slows and yellow patches appear PLUS the grass easily pulled up with little or no root growth. If possible, identify which pest you have and then treat with the relavent control, but if this is not possible then you can now treat for BOTH at the same time. Simply mix the TWO different nematodes (Nemasys Leatherjacket Killer AND Nemasys Chafer Grubs Killer) together and apply to the lawn AT THE SAME TIME.


Lawn Pest Pack - treats 100 sqm - £47.75 saving £5.00 - currently unavailable

Lawn Pest Pack Economy - treats 500 sqm - £169.45 saving £10.00 -  currently unavailable