The Best Times Of The Year To Seed (Or Overseed) A Lawn

Is your lawn looking a little scraggly or bare in spots? Thinking about throwing down some seed to fill it in and make it look thicker? Before you do, let’s talk about the best times of the year to seed a new lawn or overseed an established lawn.

Cool-season turfgrass types should be seeded in the fall.

  • Cool-season type seeds germinate best when the soil temperatures are between 50 and 60°F, or roughly when the daytime air temperatures are between 60 and 75°F.
  • Put seed down about 45 days before the first fall frost is predicted for your area. In the northern regions, this is usually from mid-August to mid-September; for homeowners in the transition zone, this is generally mid-September to early or mid-October.

Warm-season turfs should be seeded in the spring.

  • Warm-season type seeds germinate best when soil temperatures are between 65 and 70°F, or daytime air temperatures above 80°F.
  • Put seed down at least 90 days before the first fall frost, they go dormant once temperatures drop below 55°F. Homeowners living in the northern areas where warm-season grasses are grown should plant in May or June. In areas more south, the planting window expands, depending upon the climate, and is usually in April or May.

But! There is an exception to this timing. If you are overseeding warm-season lawns with cool-season grass for winter color, this needs to be done in the fall. The best time for overseeding in this manner is when temperatures drop and the lawns begin to go dormant.

Why is Timing Important?

The goal with putting down seed is to time planting with the natural period of active growth for the type of seed you’re using. Seeding at this time means the new sprouts will grow faster and stronger, giving them a great start before they start going dormant in the fall. Because the more robust the grass is going into dormancy, the better it will fare.

Cool-season grasses grow the most vigorously during late summer and early fall when the temperatures are cooler. They flourish across the cooler northern regions of the United States and into the transition zone where the cool and warm areas intermingle. Common cool-season grasses are Kentucky bluegrass, tall fescue, and ryegrasses.

Warm-season grasses have peak growth during late spring and summer when the temperatures are warm but not summer-time hot. They thrive across the Southern and Western United States and up into the bottom of the transition zone. Common warm-season grasses are Bahiagrass, Bermudagrass, Zoysia grass, and centipede grass.