Olathe, Kansas, USA
September 11, 2009
"You get what you pay for" is an old adage that´s a practical certainty for lawn seed, according to Kansas State University horticulturist Rodney St. John.
"Clean seed that has zero percent `other crop´ and zero percent weed seeds will always cost more. Highly recommended varieties with a good germination rate will cost more, too. But, they´re worth more. You might have trouble believing, for example, how just a tiny percentage of some weed seeds can ruin a yard," said St. John, who´s a turfgrass specialist with K-State Research and Extension.
He strongly suggests homeowners buy lawn seed from a reputable garden center or landscape supply provider, not a big-box store. In his experience, retailers whose year-round business is horticulture are much more likely to know the latest research results on varieties that do well locally. They also tend to be more personally involved in supplying lawn products and advice that help ensure customers´ success.
"For example, a current trend among reputable retailers is to supply blends and mixes of turf varieties, rather than to suggest people plant a mono-culture lawn. If selected well, the varieties in those products can work together to produce a stronger, better-looking lawn that´s less vulnerable to pests," St. John said.
The difference between a blend and a mix is that a blend provides several varieties of the same turf, such as a combination of three different tall fescues or a five-way blend of Kentucky bluegrasses.
In contrast, a mix combines different turf species, such as a bag with both tall fescue and Kentucky bluegrass.
Because blend seeds are from the same genus and species, they can produce a lawn with a smooth, uniform appearance, St. John said. By including different varieties with slightly different traits, however, a blend also can strengthen a lawn´s disease resistance, for example, or its ability to withstand stress.
A mix of different turf species can be good or bad, he said. Their quality mostly depends on how carefully the varieties were selected and how well adapted they are for local conditions.
Kansas mixes often combine the state´s two top turfs -- tall fescue and Kentucky bluegrass. But, the good ones often contain three or more fescue varieties and two or more bluegrass cultivars - which, in turn, provide a high-quality, uniform lawn with greater strengths in drought, disease, and insect resistance.
"Typically, these mixes are a 50-50 combination of fescue and bluegrass seeds. They won´t look equal on the label or in the hopper because fescue seeds are so much larger. In actuality, though, mixes that by volume are 80 to 90 percent tall fescue and 20 to 10 percent Kentucky bluegrass have roughly the same number of tall fescue and Kentucky bluegrass seeds," the specialist said.
Sun-and-shade mixes tend to perform in ways that are hard to predict, St. John warned.
"In most cases, they combine lots of species, in hopes that something will emerge in all of the yard´s varying degrees of sunlight. More often than not, though, the end result is a patchwork of different shades of green and differing turf textures and thicknesses.
Homeowners may not be pleased," he said.
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Moisture vital to turf seed performance
Homeowners who are seeding or overseeding a fescue lawn this September could see seedlings emerge in as few as five to 10 days. Those starting or renovating Kentucky bluegrass could see germination begin in eight to 14 days.
"You can only expect that, however, under ideal conditions in moisture, sunlight and temperature. And, if you live somewhere such as the central Great Plains, ideal weather is never guaranteed. So, you may have to be patient," said Rodney St. John, turf specialist for Kansas State University Research and Extension.
An important part of that will be continuing to irrigate the area lightly as often as needed to keep the soil surface moist (not wet), he said. That´s vital until the seed germinates and the new grass grows 1 to 2 inches tall.
"Otherwise, you´ll have a very poor germination rate," St. John said.
"Plus, if you let them dry out, the new seedlings will die."
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Weed controls can kill seedling turf
Homeowners can successfully overseed and fertilize a tall fescue or Kentucky bluegrass lawn at the same time in September or early October. Most often, though, they can´t control the dandelions, too.
"The only exception to that, of course, is if they dig up the dandelions by hand," said Rodney St. John, turfgrass horticulturist with Kansas State University Research and Extension.
The problem is that the commonly available broadleaf weed controls can kill turfgrass seedlings, he said. Most products require that homeowners apply the herbicide only after newly seeded lawns have grown enough to merit mowing two to three times.
K-State recommends a mowing height of 2.5 to 3.5 inches for tall fescue and 2 to 3 inches for bluegrass.
"If you get your seed going early enough, though, that´s not bad timing," St John said. "An early November application of a broadleaf weed control can kill dandelions quite well -- plus control henbit and chickweed. You just need to pick a day when the temperature is 50 degrees or warmer."
He added that two controls are legal and safe to use as early as seven days after turf seedlings emerge. They are Drive 75DF
(quinclorac) and Quicksilver (carfentrazone).
"They can be hard to find, however, because they´re usually considered to be professional products," St. John said. "So, homeowners who just can´t wait to control broadleaf weeds in November might have to hunt around for a while or shop on the Web. Or ... hire a lawn-care professional to do the job."
Drive 75DF only controls some broadleaf weeds, but is very effective against many grassy weeds, he added. Quicksilver is generally effective against many broadleaf weeds. Mixed together, following label directions, the two together can control a broad spectrum of problem plants in early fall.
K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and research centers statewide. Its headquarters is on the K-State campus in Manhattan.
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