UNIVERSITY PARK, Pa. -- For millions of Americans, the primary rite of spring centers on rolling out the trusty lawn mower for four months of weekend labor.

Mowing may be a thankless chore, but it reaps benefits if done correctly, says Peter Landschoot, associate professor of turfgrass science in Penn State's College of Agricultural Sciences.

"Those who want a nice lawn often are overly concerned with fertilizing and watering," he says. "But proper mowing also is an important step toward obtaining strong, vigorous grass that resists disease and weeds."

Maintain the mower

Landschoot recommends that homeowners check their mower blades before they cut their grass for the first time. "You want to get a precise, clean cut," he says. "If you haven't had your blade sharpened in a year or two, it probably needs it.

"Most lawn and garden centers can sharpen the blade or suggest someone who will do it for a reasonable fee," Landschoot says. "You may want to buy an extra blade and put it on while the original is being sharpened -- that way you can change the blade halfway through the season."

How much to cut

Homeowners should make sure their mowers are adjusted to the proper height. "Two to 3 inches is ideal," Landschoot says. "You may think you're saving yourself time by cutting your grass shorter, but this can make lawns more susceptible to heat, disease and drought stress.

"A rule of thumb is that you shouldn't take off more than one-third of the leaf blade at one time. Otherwise, you may scalp the grass and make it more vulnerable to stress."

How often to cut

The lawn's growth rate should determine how often you mow, Landschoot says. "During spring you may have to do it more than once a week," he explains. "By June, growth will slow down so you won't need to mow as often. During dry, hot conditions, there's usually no need to mow because the grass is growing extremely slowly."

Sometimes prolonged periods of rain make it impossible to mow. In that case, when the sun comes out, cut the grass with the mower blade at its highest possible setting. You can mow again a few days later with the blade lowered to the desired height.

What to do with the clippings

Landschoot recommends that grass clippings be left on the lawn or composted. "About 20 percent of what goes into landfills is yard debris such as tree leaves, hedge prunings and grass clippings," he explains. "Recycling clippings is not only civic-minded, but it's also beneficial to the lawn and saves the work involved in raking or bagging.

"If you leave the clippings on the lawn, you can cut down on fertilizer needs by as much as one-third," he adds. "Clippings break down easily, releasing nitrogen and other nutrients back into the soil."

If no herbicides have been applied to the grass, homeowners can rake the clippings and use them as mulch. Composting is another option. "If you combine clippings with tree leaves, which ordinarily don't have enough nitrogen, the two sources of yard waste will complement each other in the composting process," Landschoot says.

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Contact: Gary Abdullah gxa2@psu.edu 814-863-2708 814-865-1068 fax #172