Nematodes Against Leatherjackets (Steinernema carpocapsae)

Suffering from bare, dry patches on your lawn? There is a good chance that leatherjackets are at work. These greyish, legless larvae of the crane fly, a kind of mini caterpillar about 3 to 4 centimetres long, live under the grass and gnaw fanatically at roots at night.\nThe result becomes visible quickly: dry patches, sunken grass and a lawn that suddenly looks limp and battered. Time for a green counter-attack with nematodes!\nWhat is in the sachet?\n\nNematodes (S. carpocapsae): microscopically small, but mighty in action.\nBiodegradable carrier material: safe and environmentally friendly transport medium for the nematodes.\n\nWhen to deploy nematodes against leatherjackets?\nFrom April to October you can release nematodes on the leatherjackets – as long as the soil is at least 10°C. The ideal outdoor temperature during application is between 15 and 30°C.\nNematodes are most effective in spring (April and May) and autumn (September and October). In those months the leatherjackets are still young, small and active. Exactly the right moment to let your nematode army do the work!\nHow to put nematodes to work:\n\nMake a concentrate: Mix the entire contents of the sachet with 1 litre of lukewarm water and stir well.\nDilute before use: Pour part of this concentrate (according to the packaging) into a watering can or sprayer and top up to 10 litres of water. Stir again.\nApply: Pour or spray evenly over the lawn. Make sure you treat the entire surface.\nAftercare is key: Keep the soil lightly moist for at least two weeks. This keeps the nematodes active.\n\nTips for success:\n\nNematodes are sensitive to UV light. Use them preferably in the evening or on a cloudy day.\nThe water should be lukewarm and crystal clear. Do not add fertilisers or other additives.\nUse a sprayer with a mist setting or a special nematode spray.\nYou cannot overdose with nematodes: more is better than too few.\nStore the sachet in the fridge (4–8°C) and use the nematodes within a week of receipt. Once dissolved in water, use immediately.\n\nAfter treatment:\nStill seeing signs of activity after a week or two? Then a repeat treatment with nematodes is wise. Have the leatherjackets disappeared but the grass is still a dry carpet? Then oversow with Quick Fix repair grass seed from Joyfields for a flying, green start.