LAWN GUIDE
To help keep white curl grubs at bay, mow your lawn a little higher. Photo courtesy of Bosch.
PEST PATROL Tackle lawn-loving white curl grub with these simple and safe natural methods Photography by Diane Norris.
Words: Diane Norris ou might love your lawn, but so does the pesky little white curl grub. To check for white curl grub, place some wet hessian on a patch overnight. By early morning, the grubs should have surfaced and will be easy to spot. They are plump, C-shaped, whitish grubs with orange heads. Their bodies look segmented and their three pairs of legs are near the head. These lawn beetle larvae infiltrate lawn and feed on roots, damaging the turf. Egglaying lawn beetles can be a problem yearround, particularly in warm, wet weather from November to May. If white curl grubs have infected lawn areas, the telltale signs are: general yellowing, then browning of the grass, followed by patchy death of lawn areas. You may also notice green or brown droppings on lawn areas, and white moths flying closely over grass at sunset.
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PREVENTION METHODS
EXPERT TIP White curl grubs can intrude into garden beds and plant pots, not just lawn areas. After they have done their damage, help your lawn and other plants recover by diligently applying a seaweed solution every two to four weeks.
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Here are some great preventive measures and organic solutions to deal with this pest: Native birds: Magpies, kookaburras and grey thrush are a few of the native birds that can spot, dig up and eat curl grubs. That’s why it’s so important not to use chemical sprays. If you spray a pesticide to control curl grubs, the birds may be poisoned as well. To give the birds a helping hand, pour a bucket of cool, soapy water made with a biodegradable detergent onto affected lawn areas. The larvae and beetles will migrate to the surface, becoming easy pickings. Mowing height: Mow lawns higher, about 4cm. For those who like to scalp lawn areas, this may seem a bit long but it pays dividends. Both beetles and moths love laying their eggs
Aerating a lawn is one way to help keep it pest free. Pictured, the Cyclone Tubular Steel Lawn Aerator.
as close to the soil as possible, so longer grass discourages them. Watering: White curl grubs flourish in a moist environment. The soil in which lawn grows doesn’t need to be constantly moist. Water deeply and only when necessary. Your lawn areas will become more drought-tolerant and much less appealing to white curl grub. Aeration for lawns: Grass needs good soil to grow strong roots and regular lawn aeration is needed. You can use a garden fork or longhandled cultivator to do the job. Aeration will encourage a deep root system that’s far more resilient to grub attack.
PERSISTENT PESTS If those prevention methods are not absolutely satisfactory, the following control methods are safe to use in the organic garden. Insectkilling nematodes, known as entomopathogenic nematodes (ENs), are safe to handle, safe for plants and active only against specific soildwelling insects, such as grubs. Bacillus thuringiensis is a biological control bacterium marketed as Dipel. The solution is considered safe for bees, fish, birds and pets, and can be applied to lawn as well as other plants. It contains no poisons but it’s important to follow the instructions on the packaging. Match your irrigation system to the needs of your lawn. Shown, Pope Products’ Square Wave sprinkler.