So, your lawn is looking great and it’s the talk of the neighbourhood. You’re as proud as punch. Then, one day as you’re racing out the door, you see a small dead patch. The next day it looks a bit bigger. Before you know it, it’s too late. You take your morning coffee into your front yard to admire your beautiful lawn…and it’s gone!
In less than a week, lawn grubs can cause significant damage. That’s exactly what happened to me.
It took me a few frustrating months to repair the lawn grub damage. Just when I thought I had won the battle with lawn grubs, the yard would start showing telltale signs again.
In this article, I will explain:
- how to tell if you have lawn grubs
- what are lawn grubs?
- what do lawn grubs look like?
- how to treat your lawn grub infestation
- what to do to get your lawn looking good again.
Telltale Signs You Have Lawn Grub
Lawn grubs are most active in the warmer months. In Brisbane, that is usually from early Summer to the end of Autumn. The best time to see lawn grubs is early morning or dusk.
Lawn grub worms prefer well-fed Kikuyu and Couch lawns typical of Brisbane residential areas but tend to stay away from Sir Walter lawns and other thicker-bladed buffalo grass varieties.
Lawn grubs also love moist soil, so if you take pride in maintaining a beautiful, healthy lawn, you’re probably susceptible to lawn grub damage.
Common signs that you may have lawn grubs damaging your grass:
- increased bird activity on your lawn
- thinning or brown patches of grass
- light brown furry egg sacs on your eaves, fences, and garden furniture
- parasitic wasps – small black and orange wasps flying low above your grass
- moths flying above your lawn at dusk
- spongy lawn
Parasitic wasps are beneficial insects that eat lawn grub. There is no need to kill them. Just treat the lawn grub.
Still Not Sure If You Have A Lawn Grub Infestation?
If you’re still unsure you have lawn grub, place a wet hessian sack or wet carpet on your lawn at night. Early the following day, turn it over to see if any lawn grubs are attached to it.
You could also pour a bucket of soapy water near the edge of a patch of lawn you suspect has been eaten by lawn grubs. You may see lawn grubs come to the surface within ten minutes.
Sometimes the best way is to treat your lawn as though it does have a lawn grub infestation using a treatment that offers ongoing protection for a few months. That way, even if you don’t have lawn grubs right now, you’ll be less likely to have a grub problem later.
What Are Lawn Grubs?
Lawn grubs are lawn and garden pests that destroy your lawn. They are caterpillars, otherwise known as the larvae of beetles and moths, and there are more than 2000 species native to Australia. Lawn grubs feed on your grass roots (root feeders) or the tips (surface dwellers).
What Do Lawn Grubs Look Like?
Surface Dwellers
Three common types of lawn grub found in South East Queensland are army worm, sod webworm and cut worm. They all do the same damage to your lawn, and the type of treatment is the same.
Armyworms are the ones I see most in the north Brisbane residential areas around Warner, Cashmere, Joyner, Brendale, Albany Creek, and Eatons Hill. They are light brown caterpillars with darker brown stripes and grow up to three centimetres long. They can be hard to spot on your lawn because they blend into the soil and dead patches of your lawn.
Cut worms are similar in size and shape to army worms and may have stripes or spots on their body. They are the larvae of harmless moths, including the Bogong Moth.
Sod webworms are of similar size and shape, have brown heads, and are lighter in colour.
Root Feeders
Lawn grubs that feed on the root system of your lawn include the larvae (caterpillars) of scarab beetles and include Japanese Beetles, African Black Beetles, Christmas Beetles, and Rhinoceros Beetles.
The beetles are harmless. Only the caterpillars cause problems
The larvae of scarab beetles are called Curl Grubs or C-Grubs and are between 15mm to 60mm long. They have a soft C-shaped white body with six legs and can have black, red, yellow, or brown heads.
Adult beetles lay their eggs in the soil. When the eggs hatch, the lawn grubs feed on plant and grass roots before pupating and emerging as adult beetles.
To find out if you have curl grubs, dig through a garden bed or lift a thirty centimetre square of turf.
If you find a few curl grubs in a garden bed, squash them or collect them and feed them to the birds or chooks. Treatment is only required if you find large numbers, about 50 or more grubs per square meter.
Lawn Grub Treatment Options
There is a range of preventative measures and lawn grub killer products on the market. I have achieved the best results with products from specialist garden centres, not hardware stores. Be sure to treat your entire lawn, not just the affected areas.
Natural Treatment Options
If you treat lawn grubs early when your grub population is small, natural products are effective ways to control the problem.
Natural Predators
For small grub populations, birds, parasitic wasps, and even cane toads may control lawn grubs before you are aware of the problem. However, this is often not enough, and lawn grubs can do a lot of damage in a short amount of time.
Neem Oil
Neem oil is an organic pesticide and a natural way to kill all types of lawn grubs. You can even use it safely in your vegetable garden. If you’re trying to control surface dwellers, spray at night when they are most active.
Beneficial Nematodes
Beneficial nematodes are microscopic worms that are natural predators of lawn grubs and are an effective way to prevent and manage lawn grubs. They are not toxic to humans, pets, aquatic life, or beneficial organisms in the soil.
You can buy beneficial nematodes online, and they are dispersed in water and sprayed onto your lawn. The cost is comparable to or less than the cost of repeated chemical grub killers.
The video below outlines the application process for treating lawn grubs with beneficial nematodes.
Chemical Insecticide
You will use a different type of treatment depending on whether you are trying to prevent a lawn grub infestation or if you are treating an existing lawn grub problem.
Curative Products
If you have lawn grubs, you need to implement a treatment plan quickly, and chemical lawn grub killers are readily available. You can try grub control products from your local hardware store, but you could spend a few months, like I did, treating your lawn. Use PPE when applying grub killer, follow the directions and re-spray after seven to ten days.
Last Summer, I used products from a large hardware store and found them pretty ineffective. I followed the directions on the pack and didn’t kill off my lawn grub infestation entirely. Using two brands of lawn grub killer purchased at the hardware store, it took me five applications over six weeks to get rid of lawn grubs.
This Summer, I’ll be using commercial-grade products as a preventative measure.
Preventative Measures
If you get yourself organised, in early Spring and early Summer, you can apply a preventative lawn grub treatment rather than wait for the lawn of grubs that will inevitably occur.
The advantage of preventative measures is that you will use fewer chemicals on your lawn than you would with repeated treatments of curative products.
If you’d like to apply Acelepryn yourself, you can buy Acelepryn from your local garden centre, such as Warner Garden Centre, or buy online directly from Lawn Pride Australia. You will not find Acelepryn in hardware stores.
How To Get Your Lawn Looking Its Best After A Lawn Grub Attack
As my lawn started growing, I mowed it really short and raked through the lawn to remove the dead grass.
I then started adding nutrients to the soil by spraying the lawn with worm tea from my worm farm, but Seasol or another organic fertiliser would work just as well.
If you have severe lawn damage, applying organic matter such as compost or topsoil will help.
I also started mowing the lawn every few days to stimulate growth, but a weekly mow would suffice for the less enthusiastic gardener. Once your lawn has recovered, you can then resume fortnightly mowing.
War Horse Mowing is a veteran-owned and operated business. We provide reliable and trustworthy lawn mowing and gardening services in North Brisbane suburbs of Warner, Cashmere, Joyner, Brendale, Eatons Hill, Albany Creek, Bridgeman Downs and surrounding areas.
We offer preventative and curative lawn grub treatment services. We’re always happy to provide free advice, so feel free to contact us. If you need someone to treat lawn grub infestation, please reach out.