Lawn Grub / Soapy Water Test

The simple and effective way to see if your lawn is under attack from Lawn Grubs and you can do it all yourself.

DIY soapy water test.

Here’s how

If you have noticed of late irregular brown patches in your lawn that have died out there is a high possibility that your lawn may be under attack from lawn chewing pests.

The soapy water test is a simple and effective way to test your lawn for chewing pests that may be hiding in your soil profile and or thatch layer that is causing the damage. The main reason for this is soap and detergents irritate these chewing pests forcing them to exit the area and rise to the surface.


Step 1. Source a 20ltr bucket or something similar fill with water and add a good helping of dish washing liquid.

Step 2. Mix the water and dish detergent by hand to ensure it is thoroughly mixed and bubbles appear.

Step 3. Head to the area where the damage is present and slowly pour the mixture over the affected area as well as the surrounding healthy turf surrounding the area.

Step 4. Allow the detergent and water to saturate the thatch layer and soil profile and wait approximately 5 to 10 minutes for the chewing pests to emerge. If you get a result this is confirmation that you have lawn grubs.

Note. Repeating this process several times in different areas of the lawn is also beneficial to ascertain the extent of the infestation and population of the chewing pests you may have.

If any of the following appear after you have conducted the soapy water test you will be best to act as soon as possible to avoid further damage moving forward.

  • Cutworms (larvae)
  • Fall armyworms (larvae)
  • Tropical/Sod webworms (larvae)
  • African Black Beetle (larvae and adults)
  • Armyworm (larvae

We recommend the use of Rumbler insecticide for fast knockdown control followed by the use of Acelepryn which will provide you up to 6 months protection. 

The soapy water test is best conducted in the early morning and or at dusk when lawn grub activity will be at its highest for best results.