PUTNAM COUNTY — Keeping your lawn looking lush and green can become increasingly difficult in NW Ohio during the summertime. Excessive heat, lack of moisture, white grubs, and other factors can quickly turn a lush lawn into a lackluster one. Here are a few tips to keep your lawn thick, healthy, and in tip- top shape throughout the summer months.


Adjust your mower to the proper height. Cutting or mowing height directly affects the health of your lawn. Maintain a proper mowing height of at least 3” for most types of grasses in Ohio. A mowing height of 3 to 4” allows the grass to conserve water and withstand hot, dry summers. It also shades the soil surface preventing weed seeds from germinating and becoming established, thus reducing the need for herbicides. Grass that is 3 to 4” in height can also tolerate some grub presence compared to shorter turf.

Ideally, you want to remove no more than 1/3 of the grass at each cutting to prevent stressing the lawn. Removing more than 1/3 of the grass blade reduces the plant’s ability to take up water and nutrients to support the root system leading to a weakened plant. If your mower is set to a cutting height of 3”, you will want to mow when the grass reaches up to 4.5” tall to remove no more than 1/3 of the blades. For homeowners that like to clip grass blades close to the ground (this is called scalping) – try gradually raising the mower height with each mowing until you reach 3” - your lawn will thank you for it! Lawns also need about an inch of water a week to remain green and lush. Summer rainfall is generally spotty across Putnam County and may or may not supply enough water. Most grasses will go dormant during hot, dry periods if they are not adequately watered. Dormant grass is brown but still alive and will resume growth once ample moisture returns.

Homeowners will also want to be on the lookout for white grubs in the lawn. Grubs are notorious for causing patches of dry, dead grass in once-lush lawns. Many different beetles that we find out and about during June and July – such as Japanese beetles, chafer beetles, June beetles, Asiatic garden beetles, and a few others – all lay their eggs in the soil beneath turfgrass during July and August. These eggs hatch into white, C-shaped grubs that feed on grass roots, killing the grass and causing brown patches. Additional damage can occur from wildlife like skunks and other animals that enjoy feeding on the grubs.

How does one control grubs in the lawn? First, homeowners will want to make sure the problem is indeed grubs. Peel back the turf from the soil surface and examine for 3/4” C-shaped grubs. In non-irrigated lawns, these will likely be masked chafer grubs while in irrigated lawns, they will most likely be Japanese beetle grubs.

Once grubs are identified, select an insecticide that contains one of these active ingredients: imidacloprid, thiamethoxam, clothianidin or chlorantraniloprole. These are considered preventive products that control newly hatched grubs found in lawns during July and August. These insecticides work best on small grubs and lose the ability to control larger grubs in the fall through spring. Once applied to the turf, the products need to be watered in immediately with 0.5 to 1” of water to do their job.

Hopefully these few tips will help keep your lawn looking great throughout the summer! For additional information, please contact the Putnam County Extension office at 419-523-6294, at scheckelhoff.11@osu. edu, or stop in at 1206 East Second Street in Ottawa. You can also find us on Facebook by searching for OSU Extension Putnam County.