Japanese Beetles

Asked April 5, 2019, 12:16 PM EDT

Last year I had some Japanese Beetles evident in my perennial hibiscus plants as well as in some other perennials around the beds surrounding my lawn. My lawn service is suggesting that I have my lawn sprayed with grub control spring and again in the fall. Do you see this as a possible solution? What other things should I do as well? Any help you can give me would be greatly appreciated
If you recommend the grub spray what is th time frame for doing it this spring
.I'm wondering how soon it should be done. Thank you

Hennepin County Minnesota

1 Response

If you are concerned about the presence of adult beetles damaging your plants, grub control in your lawn will do little or nothing to reduce their numbers. The beetles are strong fliers and will come from a considerable distance to feed on your plants.

However, if Japanese beetle grubs are damaging your lawn significantly by feeding on the roots, spraying to control them may be beneficial. Digging up a portion of damaged turf in summer to see whether grubs are present and in what numbers is the best way to assess this possibility.

Information in the following bulletin explains how to do this. It also explains what products to apply and when to apply them if grub control is needed. Generally speaking, spring is not the optimum time to control Japanese beetle grubs.