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How do you kill lawn grubs?

lawngrub.jpgArmyworms are hideous creatures. Unfortunately because they are fast moving and do their damage overnight they can be hard to treat and are often only spotted once they've done the damage. Rule one is to identify them accurately and rule two is act quickly. 

I would use EcoNeem. Although expensive, it is very effective and much safer to use. Scotts Lawn Builder Grub & Insect can be very effective too.

Personally I’d avoid any products (lawn care or otherwise) that have Imadicloprid as an active ingredient as the environmental side-effects of these products are terrible. Reports are also indicating that target insects have a high level of resistance to these products.


Products containing Imadicloprid & other "neo-nics" have actually been banned in various places around the world as they are considered to be major contributors to the decline of essential pollinators such as bees. As the product is systemic even when used on a lawn it can be taken-up through the soil by flowering plants in surrounding garden beds and then gets to bees, etc. In other words these products are not killing the critters you want to nuke but are killing the good guys in your garden. - Adam_W 

If you've had grub infestation before, I suggest following @Adam_W's recommendation and using Scotts Lawn Builder 4kg Grub + Insect Slow Release Lawn Fertiliser. It's never too early to do some preventive maintenance especially when it comes to curl grubs. Just remember to use the product as directed. - EricL

Note that the generic term lawn grubs is used in Australia for two different pests: armyworms that eat the leaves of lawn and curl grubs that feed on the roots of grass and other plants.


If you find curl grubs in a garden bed, assess how big your problem is. Consider how many would can find within a square meter. If it's just one or two, it is no real cause for great alarm. If you have more than 10 within the square meter, it's time to control them.


I'd suggest using Multicrop 2L EcoGrub 3 In 1 Insecticide in a vegetable garden. It's not a scheduled poison but an organic insecticide. The optimum application time is between mid Spring to mid Summer when the eggs are hatching and larvae are near the soil's surface. You'll also need to ensure thorough coverage of treated areas.


If you continue to have an issue with them, spraying at regular intervals throughout the year will prevent them from being able to grow and cause damage. When you come across large grubs, throw them out onto the ground, and your friendly neighbourhood magpie will make short work of them. They can be used as a bartering system in Spring. The more you feed to the magpies, the less likely they are to swoop you.


An alternative to spraying the ground and dealing with these curl grubs is to utilise raised garden beds. We have a fantastic range that you might like to check out. - MitchellMc

If you have found curl grubs in a pot, I'd try a soil drench of ecoOil or neem oil, both of which can be safely used for the treatment of edible plants. Read the labels for instructions on how much to use per litre or bucket of water, mix it well and pour into the potting mix until excess drains out the base of the pot.


The curl grubs possibly found their way originally into the pot through drainage holes - stand the pot up off the ground on pot feet or some bricks to prevent this happening again. The other way they can enter potting mix is if an opened bag of mix has been stored outdoors or on the ground where the grubs or the adults may have access. If you have to keep an opened bag for short period, make sure to put it in a shed and up off the ground and fold the top over securely. - Noelle

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