Wait for fall to reseed cool-season grass

“Extension on the Go” podcast by Debbie Johnson. Episode 68: Reseeding Cool Season Lawns

COLUMBIA, Mo. – If you’re thinking of reseeding your lawn now that warm weather has arrived, think again.

“If you look at the calendar, we’re in May. Any grass seedling will have to fight against weeds, disease and insects,” said Brad Fresenburg, a University of Missouri Extension turfgrass specialist. “The new grass seedlings will suffer and very likely not be successful.”

Spring reseeding of cool-season grasses needs to occur in late February and early March. For many homeowners, that wasn’t possible this year because the ground was covered with snow, said Fresenburg, who is also an assistant professor in plant sciences at the MU College of Agriculture, Food and Natural Resources.

“The primary time to seed a cool-season grass is in the fall,” he said. But there are things you can do now to get ready for fall reseeding.

“As we get to the end of the spring season you may find some good deals and sales on grass seed,” Fresenburg said. “Buy your seed now and store it in a cool, dry place until that first week of September, which is a much better time to plant that seed.”

Tall fescue and Kentucky bluegrass seed mixtures tend to do best in Missouri.

“The ratio of that mixture is 90 percent fescue with 10 percent bluegrass,” he said. “If homeowners can find those two types of seed products on the shelves, those are the ones that we usually recommend for cool-season lawns in Missouri.”

Avoid seed mixtures that contain perennial ryegrass.

“Ryegrass may look great in some areas of the country, but they do tend to suffer in the transition zone here in Missouri,” Fresenburg said. “The heat and humidity of Missouri’s summer makes ryegrass very susceptible to diseases.”

Tall fescue is best suited for Missouri’s summer heat and late summer dryness.

“The fescues in general have a deeper root system than a Kentucky bluegrass or ryegrass,” he said. “So when we get into July and August here in Missouri, it can pull water from deeper in the soil profile and keep the air-conditioning system going within that plant.”

For more information, the following MU Extension guides are available for free download: