Extension Educator, Horticulture
For better or worse the drone of busy lawn mowers is heard throughout the summer. However, I do prefer the clack, clack, clack of people powered reel mowers. Sometimes a few grazing sheep seem like a better, quieter option but then you have to worry about more than piles of grass clippings on the lawn.
It may seem like just another chore but actually how a lawn is mowed can have an impact on lawn appearance and lawn health. Here are a few simple guidelines for proper mowing.
Mow at the proper height. Unless golf balls are involved, don't mow it short. Mowing the lawn short may seem like a good idea so you don't have to mow as often. Letting the lawn get tall than mowing it short is not a good idea. For most lawns, a mowing height between 2 to 3 inches is best. When the weather is cool and the grass is growing rapidly, the two-inch height is fine. As the weather gets hotter and drier and grass growth slows, height should be raised to three inches. Also in the shade grasses should be mowed at the three-inch height. Lawns mowed at higher heights tend to have deeper roots, less weed problems, and look better. Scalping opens up areas of the lawn to weed invasion. Something as simple as raising the mowing height can have a major impact on the quality of many home lawns.
Avoid removing more than one-third of the leaf blade at any one mowing. In other words don't let the grass get above three inches to mow it to two inches. I know this is tough when the grass is growing fast. If the grass gets out of control, don't immediately mow it to two inches but instead gradually take it down to the lower height over a couple mowings. Try to mow at the rate of grass growth rather than the day of the week. Also don't mow when the grass is wet.
Return clippings to the lawn when feasible. Unless you see big piles of grass left after mowing, clippings do not need to be collected. Small clippings readily decompose (contain 75 - 80 percent water) and do not cause thatch. Clippings also recycle nutrients, in particular nitrogen, so less fertilizer is needed. Mulching mowers are not really necessary. A study at the University of Illinois showed mulching mowers did not provide any additional benefit over conventional rotary mowers returning clippings, assuming proper mowing frequency and lawn fertilizing was followed.
Keep mower blades sharp. If the grass blades look ragged on the tips, it's time to get the blades sharpened. Ragged grass blades can lead to leaf disease problems and detract from the lawn's appearance.
Mow in the direction that is safest. Mowing in criss-cross patterns or periodically mowing in different directions is fine, but not really necessary unless again, golf balls are involved.
Check out our website for more great info on lawns. http://www.urbanext.uiuc.edu/hort/