Homemade Grub Killer Recipe: Does Dawn Dish Soap Kill Grubs?

You can control grubs using a commercial grub killer or a homemade recipe such as Dawn dish soap. But just how effective is a homemade grub killer recipe and does Dawn dish soap kill grubs?

Get the Dawn Liquid Dish Soap for this procedure here.

Does Dawn Dish Soap Kill Grubs?

Dawn dish soap kills grub worms by smothering them until they die. The soapy solution covers the surface of the grubs and suffocates them.

The grubs will die within a few minutes and the residual effect can last up to 24 hours if you are using an insecticidal soap in your homemade recipe. Insecticidal soaps offer several advantages and are regarded as the safest pesticides to use.

Dish soap is good at disrupting the cell membrane of soft-bodied insects such as grub worms, sod webworms, and cutworms. That is why it is an effective treatment for Japanese beetle, June, and May beetles in lawns.

How to Spray Yard with Dawn Dish Soap?

Dish soap or any other household soap will work well for this natural formulation. Some people mix in some lemon, but it is not necessary. If you don’t have dawn dish soap, you can use an insecticidal soap.

Here’s how to use dawn dish soap to kill grubs in your lawn:

1. Add 3 tablespoons of liquid dawn soap in 1 gallon of water.
2. Stir thoroughly to make a soapy liquid.
3. Spray the soapy liquid onto the areas with brown patches of dying grass.
4. Wait for about an hour.
5. Dig up a square foot of your treated lawn and check if there are grubs.
6. Treat with the dawn dish soap again if there are some grubs still alive.

Pro tip: If you want to make the DIY solution more potent, you can mix liquid dish soap with lemon and mouthwash and then spray it all over the lawn. It will act as a grub worm deterrent and killer without causing any damage to your grass.

The right time to treat for grubs in the lawn is between spring and summer. This is the time when the Japanese beetle larvae are very active feeding and developing into adult beetles. See also my article on white grub lifecycle.

Controlling them at this time means you will stop the damage come the next season.

• The dish dawn soap solution is also used to check for grubs and the extent of their damage.
• If you notice there are more than 5 grubs per square foot, the infestation is too of concern.
• You may want to consider using more effective natural grubworm killers or even chemical solutions.
• Milky spore and nematodes are a great natural solution you can try but milky spore also have some disadvantages.
• Packaged top-quality grub killers include GrubEx, BioAdvanced Grub Killer, and Sevin.

Is Dish Soap Effective for Grub Control?

It is a given that dish soap can kill grubs in your lawn or garden, but how effective is it?

Flushing white grubs from underneath the lawn using dish soap is not possible. The best method you can use to check if there are grubs is to dig up a square foot of the lawn a couple of inches deep and inspecting if there are grubs damaging the roots.

Testing

I have tested the effectiveness of using detergents and insecticidal soaps to get rid of grubs in infested lawns and while it works, there are a few limitations to this method.

In early spring when white grub worms start to damage the lawn, you’ll notice brown patches and spots in your lawn. If the damage is small and limited, you can control the grubs using dawn dish soap.

However, for extensive damage over large areas of the lawn, it is very difficult to control grubs because you’re spraying on top of the lawn while grub worms continue to cause damage to the roots. For a large outbreak of grubs, the best treatments are chemical pesticides.

For you to have any success, you may need to pour large amounts of soapy water on your lawn to smother grubs.

I found this to be a practical solution for small areas of infestation. Large yards will require a lot of this application of dawn dish soap to kill grubs effectively.

Summer treatments

Japanese beetles, in their adult stage, can be killed in the lawn using dish soap. The soap dissolves their exoskeleton and interferes with their cell membranes. The soapy cover suffocates them to death.

Dish soap however should be used as a weed deterrent instead of a natural insecticide of fungicide.

If you see these in your lawn, it is time to spray some dawn dish soap all over the yard – generously. This treatment will reduce their population before they lay their eggs and help control the infestation for the next season.

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References

• Molly College: 12 Steps to an Organically Green Lawn – Step 9 Grubs and Other Pests
• The University of Tennessee Institute of Agriculture Extension: Lawn Insects: How to Control Them
• University of Georgia Extension: White Grub Pests of Turfgrass

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