Most St. Louis lawns are tall fescue, and one of the easiest ways to keep it healthy is simply not cutting it too short.
The right height
University of Missouri Extension recommends mowing turf-type tall fescue at 3 to 4 inches. Taller grass shades the soil, holds moisture better through hot, dry stretches, and crowds out weeds that need sunlight to sprout.
The one-third rule
Never take off more than about one-third of the grass blade at once. Cutting too much at one time stresses the lawn and can leave it looking brown or scalped. During fast spring growth that can mean mowing more than once a week. As growth slows in fall, mow when the grass needs it rather than on a strict schedule.
Leave the clippings
MU Extension also recommends against bagging clippings. They break down quickly and return organic matter to the soil.
Summer heat
When July and August hit, we keep the mowing height up to help lawns ride out the heat, and we keep blades sharp so the grass is cut cleanly instead of torn.