How to Check a Lawn for Grubs
- 1). Pull back the sod in dead areas of grass where grub infestation is suspected. Count any grubs found in the root zone underneath. The University of Illinois Extension says a population of 10 or more grubs per square foot can lead to browning.
- 2). Retrieve a flat-edge spade if grubs are found in the initial testing area.
- 3). Use the spade to peel back a 6-inch square section of turf.
- 4). Inspect the first 3 inches of soil for white grubs. Grubs look like short, fat, white worms curled into a rough "C" shape. Count the number of grubs found in this area.
- 5). Repeat the procedure throughout the yard. The University of Rhode Island Landscape Horticulture Program suggests taking at least a dozen samplings, and to treat the yard if more than two or three grubs are found per area.
