Unsightly yellow patches on lawns can be an early warning sign of a potentially devastating pest infestation that can wreak havoc on gardens.
As the mild spring weather encourages people to tend to their outdoor spaces, lawn experts are urging them to be on the lookout for signs of leatherjackets, a common pest that destroys grass from the roots up.
Ben Agnew, a grass expert at Lawnsmith , warned: “Although small, these grubs can be a nightmare for your lawn. An infestation can undo all the hard work you’ve put in and leave you with nothing. “They thrive by eating the roots of grass and plants, killing their food source as they go. As they exist under the surface of your lawn, the first sign of an issue is your lawn dying, leaving yellow patches that then turn brown.
“Crane flies, also known as daddy long legs, lay eggs in most UK gardens, usually at the end of summer. The damp, wet conditions experienced in the UK during winter create the perfect environment for the eggs to hatch into leatherjackets.”
These pests are legless grubs with tough, leathery skin, typically grey or brown in colour, and can grow up to 3 cm in length,” Ben added. “Prevention is easier than the cure for a leatherjacket infestation. Effective treatment comes in the form of microscopic bacterial worms, called nematodes, specifically ‘Steinernema feltiae’.
“Nematodes get rid of leatherjackets by infiltrating their outer casing and subsequently killing them. “Leatherjackets can cause considerable damage, and even after treatment, it can be challenging to restore your lawn to its former state. “Crane flies, also known as daddy long legs, lay eggs in most UK gardens, usually at the end of summer. Damp, wet conditions, like the UK experiences over winter, creates the perfect conditions for the eggs to hatch into leatherjackets. It can take your garden some time to return to its former glory.”
The best course of action, according to Lawnsmith’s expert, is to remove dead patches of yellowing and browning grass and re-seed the area. Applying a fertiliser across the whole lawn can help maintain its overall health.
Lawns with poor drainage are more likely to suffer from a leatherjacket infestation, so addressing this problem is the best defence. “Aerating your lawn can help improve drainage. To do this, simply create holes in the turf to allow it to breathe and encourage water to disperse,” Ben explained.
Heavily shaded gardens can also suffer, so removing thick branches of overhanging trees and bushes can help more sunlight reach the turf.
“Some soils are better than others for drainage. For example, nutrient-dense clay soils can make gardens more prone to flooding. If you often see water pooling in your garden, investigate the type of soil so you know how to nurture the lawn correctly.”