Released April 2, 2009
MANHATTAN, Kan. -- Horticulturist Ward Upham has mixed feelings about the best way to answer this annually repeated question: “Should I mow my lawn pretty short in spring?”
“The only honest answer to that is ‘yes and no,’” said Upham, who heads the Master Gardener program for Kansas State University Research and Extension.
One reason he’s hesitant to endorse short-height springtime mowing is simple. Yet, it’s vitally important to the survival of some lawns in the central United States, given the region’s oft-stressful weather.
“Root depth and mowing height are related for such upright-growing turf grasses as tall fescue and Kentucky bluegrass. Those are Kansas’ No. 1 and 2 favorite lawn turfs. The higher they’re cut, the deeper their root system will be,” Upham explained.
Unless such cool-season turf varieties are watered well and often through summer, they’ll react to the season’s heat and drought by going dormant, he said. If they have deep roots, however, their dormancy period will be shorter. And, in almost every case, the turf will survive.
“At the same time, it doesn’t hurt to mow lower than normal height the first time or two, so long as you don’t ‘scalp’ any parts of your lawn. As a matter of fact, that can speed green-up by removing the old, dead grass and allowing the soil to warm up faster,” Upham said. “Setting your mowing height at 1 to 1 ½ inches should be about right.”
Then, however, the mower must go up to its tested, recommended mowing height -- 2 ½ to 3 ½ inches high for tall fescue and 2 to 3 inches for Kentucky bluegrass.
“Most weed seeds – including crabgrass seed – must have light to germinate,” Upham said. “A high mowing height allows turf to shade the soil and curb its own weed pressure.”
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http://www.oznet.ksu.edu/news/story/briefs040209.aspx
Contact: Elaine Edwards, elainee@ksu.edu
