Lawns across Iowa have turned a beautiful, dark green with the recent rains. The greening of the lawns signifies the arrival of spring and the start of the lawn mowing season. Proper mowing practices over the next several months will help keep the lawn attractive and healthy.
Mowing height and frequency are the most important aspects of mowing. Bluegrass lawns should be maintained at 2 1/2 to 3 inches in the spring and fall months. Set the mower blade to a height of 3 to 3 1/2 inches during summer. Mowing frequency is based on the growth rate of the turfgrass. As a general rule, never remove more than 1/3 of the total leaf surface at any one mowing. For example, to maintain a lawn at 3 inches, the grass should be mowed when it reaches a height of 4 1/2 inches. In the spring it may be necessary to mow every 4 to 5 days, possibly only once every 1 to 2 weeks in summer, with more frequent mowing again in the fall. Irrigation and fertilization practices, and weather conditions dictate mowing frequency.
Mowing grass that is much too tall is hard on the mower and, more importantly, is harmful to the grass. It weakens the turfgrass allowing weeds to move into the lawn. It may take several weeks for the grass to recover from a severe mowing. Another problem is the large amount of clippings. Excessive amounts of clippings are unsightly, tend to smother the turfgrass and create an environment that favors disease development. Grass clippings should be bagged or raked and removed when mowing grass that has grown too tall.
Grass that has gotten extremely tall should be mowed as soon as possible. Raise the mower blade as high as possible, mow, and remove the grass clippings. Gradually reduce the height of the grass in later mowings until the lawn is being mowed at the proper height.
When the lawn is mowed properly, the grass clippings do not have to be removed. The small clippings will simply filter down into the turf and decompose quickly, returning essential plant nutrients to the soil. Lawn clippings do not significantly contribute to thatch development.
Mow the lawn with a sharp blade. Sharpen the mower blade each spring. Thereafter, inspect the blade after each mowing and sharpen as needed. A dull blade tears the ends of the grass blades. The damaged tissue dries out giving the turf surface a whitish appearance. Also, the torn leaf tissue losses greater amounts of water and increases the possibility of disease problems.
Alternate your mowing pattern or direction each time the lawn is mowed. Repeatedly mowing the lawn in the same direction pushes the grass over rather than cutting it cleanly. Also, different mowing patterns reduce soil compaction and wear from the mower wheels.
Because mowers can cause serious injuries to the operator and others, follow safety precautions when mowing the lawn. Dress appropriately, wear sturdy shoes with slip resistant soles and full length pants. Remove all debris including branches, stones, and toys from the lawn before mowing. Keep children and pets at a safe distance to protect them flying debris. Keep hands and feet away from the blade when the mower is running. Never leave the mower running unattended (new models automatically shut off). When using a walk-behind mower, mow across a slope rather than up and down. You are less likely to slip under the mower when mowing across a slope. Always push rather than pull the mower. Proper, careful mowing will help protect the health of the turf and the operator.
This article originally appeared in the April 9, 1999 issue, p. 39.