The Right Mowing Height for Chicago Area Grass

One of the most common lawn care mistakes in the Chicago suburbs is cutting grass too short. It feels counterintuitive — shorter should mean less mowing, right? The reality is that cutting cool-season grasses too low is one of the fastest ways to stress your lawn, invite weeds, and create bare patches that are difficult to recover.

Most lawns in the Southwest Chicago suburbs — including Chicago Ridge, Oak Lawn, Burr Ridge, Orland Park, and Tinley Park — are composed of cool-season grasses. Kentucky bluegrass, tall fescue, and perennial ryegrass are the most common varieties. These grasses thrive in spring and fall and go through a natural stress period in summer heat. The way you mow directly affects how well they handle that summer stress.

The recommended mowing height for cool-season grasses in the Chicago area is 3 to 3.5 inches during spring and fall, and 3.5 to 4 inches during summer. The extra height in summer shades the soil, retains moisture, and protects the root system from heat stress. When grass is cut short in summer, the soil heats up faster, moisture evaporates more quickly, and roots become shallow and vulnerable.

Never remove more than one-third of the grass blade in a single mowing. This rule — called the one-third rule — is the most important mowing guideline in lawn care. Cutting off more than one-third at once shocks the plant, redirects energy from root development to blade regrowth, and leaves your lawn temporarily weakened and more susceptible to weeds and disease.

Mowing frequency matters as much as height. During peak spring growth, a weekly mowing schedule keeps most Chicago-area lawns at the right height. In mid-summer, growth slows and bi-weekly mowing may be sufficient — though this depends on rainfall and temperatures. In fall, growth picks back up and weekly mowing becomes important again, especially as the lawn is preparing for winter.

Blade sharpness is another factor that most homeowners overlook. A dull mower blade tears the grass rather than cutting it cleanly. Torn grass tips turn brown, creating a ragged appearance and making the lawn more susceptible to disease. Sharp blades should be standard practice — our crews maintain sharp blades throughout the mowing season.

For commercial properties, proper mowing height is especially important. A commercial lawn that is consistently cut at the right height looks dense, green, and professionally maintained. Clients, tenants, and visitors notice. A lawn that has been scalped or irregularly mowed signals neglect — regardless of how clean the rest of the property is.

At Reliable Lawn Care Company we have been mowing Southwest Suburbs lawns to the correct specifications since 1993. Our crews are trained on proper height and frequency for Illinois cool-season grasses — residential and commercial. The difference shows every week.