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How to Control Grubs in the Landscape

This post is all about how to control grubs along with tips on how to spot grub damage symptoms.

What are grubs?

The larval stage of scarab beetles are referred to as grubs; they are normally C-shaped, and white or whitish in color with brown heads.  Turf grass roots are especially tasty to grubs, but they may also feed on landscape plant roots.

Symptoms of grub damage

Symptoms of grub damage include yellowing or browning of grass leaves and thinning lawn areas.  Lawns may look drought stressed, even if they are getting adequate rainfall or irrigation. Often times, fall damage from grubs doesn’t show up until areas fail to green up the following spring.  Affected grass might be easy to pull up, due to loss of root system.  Additional damage may occur when animals root up lawn areas in their search for grubs. If you have seen one grub, you have many.

Yes, grubs like all landscape plants!

It’s early October, but the temperatures are more like late September. Grubs are still very active, as we found out recently.  We had a customer whose shrubs (compacta holly) kept declining, with more and more individual branches dying back each week.  There was no evidence of any disease or insect issue on the top growth of the plant and it was being appropriately watered.  We dug them up and the issue was immediately discovered.  Many grubs were present and feeder roots, the smaller roots that take up water and nutrients were not… grubs had made a meal of them.

 

Stopping the life cycle is key; many people wait until spring to treat, even if they know they are present in the fall.  The issue will continue to get worse; treating in the fall will reduce your spring population. If you haven’t treated yet this fall and see possible symptoms in lawn or landscape beds, it’s time to treat for grubs!

Grub control treatment

Treatment is necessary for grub control; they do not go away on their own.  It is also necessary to treat for several years; if you had grubs last year, treat this year also.  Although many products indicate that they treat for a full year, multiple applications (at least 2 per year; one in late spring and one during fall) should be applied for best results.  We carry a granular product called Bayer Complete Insect Killer and a liquid grub control called Hi-Yield Systemic Insect Spray.  These control methods also treat for other lawn pests ticks and fleas.  As with any chemical control, read labels carefully and follow application directions.