Overview
Treat The Active Grubs In Your Lawn
After you have completed a thorough grub inspection, you can begin to treat the active grubs in your lawn. It is always best to apply a grub preventative treatment prior to egg hatch and prior to seeing lawn damage. If you miss this window and are already seeing damage to your lawn from grubs you will need to apply a curative treatment. Curative treatments kill the older grubs that are currently active in the soil.
Apply Curative Treatment
Some products are only able to eliminate the very earliest stages of grubs and will not work on the older grubs that are causing damage to lawns. Curative white grub killer products are applied in late summer after grub eggs have hatched and grubs are active near the surface of the soil. Here are some important things to keep in mind:
- Curative treatments generally only stay active in the soil for a short, which means they must be applied at the right time.
- Since most grubs hatch in mid-July through mid-August, this is generally the right time to apply your curative products - see below for our pro picks for curative grub treatments. However, contacting your local extension office to speak to the master gardener about the best time to treat white grubs in your area.
- (It is best to apply preventative grub treatment products in mid-June to mid-July so it can be in the soil before the eggs hatch. See our Grub Prevention Guide for product recommendations and details on preventative treatments.)
- The thatch layer in your lawn should be less than 1/2 inch thick. If the thatch layer is thicker than 1/2 inch you will need to remove it. Thatch layers encourage pests and also stop insecticide applications from getting down into the soil where grubs are present.
- Apply a product that is labeled for active grubs. Curative grub products typically come in two formulations, liquids and granules. Both formulations work well and you should choose the formulation that is easiest for you to apply. Most curative grub products require the application to be watered in to move the product down into to the soil where grubs are active. Be sure to read and follow the product label for best results.
- A second application may be needed to help eliminate those grubs that were not near the surface at the time of the first application.
Pro Tip
Milky spore is a common grub treatment, but it will only affect Japanese beetle white grubs. This is why it is important to identify the grub before deciding to treat. Milky spore comes in two formulations, granules and powder. The granules must be applied multiple times over two years using a spreader. The powder only has to be applied one time using a specially designed applicator. It does take about 2 years to see the initial results but the spore keeps working to control grubs for at least 10 years.
Grub Treatment Infographic
(Click to Enlarge)
