UNIVERSITY PARK, Pa. -- Early fall is the best time to plant new lawns. A turfgrass specialist in Penn State's College of Agricultural Sciences offers tips for choosing seed. "The seed to use depends on whether you want to repair damaged areas or put in a new lawn," says Peter Landschoot, associate professor of turfgrass science.
Perennial ryegrass for dead patches
To seed dead patches or thicken your lawn, Landschoot suggests using perennial ryegrass. "Perennial ryegrass germinates and establishes quickly, and can accept light traffic within eight to 10 weeks," he says. "Perennial ryegrass is a dark green, fine-textured species that's compatible with Kentucky bluegrass. Chances are you already have some in your lawn."
Unlike Kentucky bluegrass, which takes two weeks to germinate and a few months to establish, perennial ryegrass should mature before the hot, dry summer months, when new seedlings are susceptible to drought.
Landschoot suggests avoiding annual ryegrass, also known as Italian ryegrass, which is one of the most commonly sold grass seeds. It's also found in some professional landscaping mixes. "Annual ryegrass may establish a few days before other ryegrass," he says, "but most people don't like its coarse texture. It thins out quickly so that after a few years, you're back to ground zero."
Landschoot also suggests avoiding the perennial ryegrass variety "Lynn," a common, inexpensive and notoriously bad seed that fades from a lawn over several years.
Fine fescue for heavy shade
Homeowners who have a large spreading tree under which the lawn has thinned may need to reseed with specialty grasses. "Heavy shade and grass don't go together well," Landschoot says. "But if the site receives more than three hours of direct sunlight daily, you probably can establish a fine fescue. Red, creeping red or Chewing's fescue do well provided you have well-drained soils."
Till and rake the soil as if starting a new lawn. "The grass needs time to establish before the trees leaf up and make shade next summer," he says.
Landschoot suggests fixing any drainage problems. Landscape plants -- grasses included -- generally don't do well in poorly drained soils.
"For areas that get fewer than three hours of direct sun, use a shade-tolerant ground cover, such as myrtle or pachysandra," he says.
Establishing new lawns
Since most yards are not completely sunny or completely shaded, Landschoot suggests using a mix of species for new lawns. "A diverse seed mix ensures that your lawn will thrive under different conditions," he says.
Sun (with some shade). For a sunny lawn with some trees, Landschoot suggests a mix of 40 to 60 percent Kentucky bluegrass, 30 to 40 percent fine fescues and 10 to 20 percent perennial ryegrass. "The Kentucky bluegrass and ryegrass will predominate in the sunny areas and the fine fescues do well in the shade," he says.
Another good choice for a sunny lawn is tall fescue, a drought-tolerant, low-maintenance species. "Buy a good quality, 'turf type' tall fescue from a reputable dealer," he says. "Stay away from the variety Kentucky 31. Most people are dissatisfied with its large, coarse clumps.
"During a drought, tall fescue will be the only green grass in the lawn," he adds. "But plant tall fescue alone. Its light-green color and coarse texture don't blend well with the finer turfgrasses, such as Kentucky bluegrass, ryegrass and fine fescue."
Shade (with some sun). For a shaded lawn with some sunny areas, Landschoot suggests a mix of 50 to 60 percent fine fescues, 30 to 40 percent Kentucky bluegrass and 10 to 20 percent perennial ryegrass.
"Don't rely on brand names, or choose a seed because the bag says it's a sun or shade mix," he says. "Read the label to learn the grass species included, the percentage of each seed and the date of the germination test. For best results, the test date should be within nine months of purchase. The germination percentage should be at least 80 percent -- preferably higher.
"A lot of companies market something called Penn State Mix," he adds. "Penn State University has absolutely nothing to do with these companies, the makeup of the mix or the seed. These mixes can contain just about anything -- sometimes you'll find it's a good mix, but sometimes it's very poor quality."
Because new lawns are a lot of trouble and expense, Landschoot recommends that you don't scrimp on seed. "Do your homework," he says.
"Store leftover seed in a cool, dry place and use it within one year," Landschoot says. "Seed can pick up moisture on a cement floor. The best place to store it is on a shelf, in a garage where the temperature stays below the 90s.
"Be sure to use a mouse-proof container," he adds. "Mice love seed."
For information on preparing a new lawn, see the Penn State College of Agricultural Sciences publications, "Turfgrass Seed and Seed Mixtures" and "Turfgrass Establishment." Single copies are available for free Pennsylvania residents from county Penn State Cooperative Extension offices. Out-of-state residents can contact the College of Agricultural Sciences Publications Distribution Center (call 814-865-6713). Publications also can be previewed or printed for free on the Web at http://pubs.cas.psu.edu/.
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EDITORS: Peter Landschoot can be reached at 814-863-1017.
Contact:
Kim Dionis KDionis@psu.edu 814-863-2703 814-865-1068 fax