Fall is the best time to plant cool-season grasses.
When your sights are set on a thick, lush lawn, planting seed represents an investment of time, money, labor and hope. From seeding new lawns to repairing rough spots and renewing existing turf, proper timing separates sweet success from something less. Your best time to planting grass seed depends on the type of lawn grass you grow and where you live. Understanding your options and getting timing right helps you seize every opportunity for seeding success. Why timing matters...Grass grow fastest and strongest when your planting season aligns with the seeds' natural periods of active growth. Just as with other kinds of plants in your landscape, lawn grasses vary in their growth cycles and regional climate preferences.
Cool-season grasses such as Kentucky bluegrass, perennial ryegrass and tall fescue, grow most vigorously during cool temperatures of late summer and early fall. These grasses flourish across cooler northern climates and into the challenging "transition zone", where cool and warm regions overlap.
Whether you grow cool or warm season grasses, timing your seeding to take advantage of your grass type's natural periods of peal growth helps seed germinate and establish quickly. Your seed gets off to the best possible start and on track for both short and long term success.
Why Fall is the best for cool-season grasses. Several distinct advantages make fall the best time to plant cool-season grass seed. In early autumn, the soil is still warm from months of summer sun. This combination of warm soil, moderate day temperatures and cool evenings encourages fast germination and establishment of newly sown cool-season grass seed.
Cool-season grass seed germinates best when soil temperatures are between 50 degrees Fahrenheit and 65 degrees Fahrenheit. This roughly corresponds to daytime air temperatures in the 60 degree Fahrenheit to 75 degree Fahrenheit range.
An inexpensive soil thermometer, available at most garden stores, can help eliminate the guesswork.
The farther north you live, the earlier cool fall temperatures and ideal planting time come. As a general rule, plant cool-season grass at least 45 days before the estimated date of your first fall frost, before soil and air temperatures drop to less favorable levels. Your grasses will enjoy a full fall season, plus a second cool, growing season come spring. Kitsap County frost season is coming up this month, so if you plan to plant seeds this fall do it soon. Mild climate weather here in Kitsap County makes for a little leeway for fall planting.
Newly planted seed needs consistent soil moisture, and fall planting offers benefits on that front too. Fall typically brings more precipitation, which lessens the chance that cool-season seeds may dry out, and reduces the need for extra watering on your part. Using premium drought-tolerant, water-conserving grass seed products, lowers the risk of problems even more.
What to expect from newly planted seed. Proper timing allows all types of grass seedlings to root well and get established before natural stresses hit. What that looks like in your lawn can vary depending on your grass type, your growing region and the condition in any given year.
Grass types and varieties vary in their natural germination speeds. For example, cool-season Kentucky bluegrass germination can take two to three times as long as tall fescue varieties. Similarly, warm-season Zoysia grass may take two to three times longer than bermuda grass. In addition, many seed products include a mix of seed types that germinate at different speeds.
Whether you are repairing bare spots, overseeding an existing lawn or starting from scratch, you can generally expect grass seedlings to emerge within seven to 21 days when grown under proper conditions. It may take another three to four weeks of grown before grass is long enough to mow. For fall-planted seed, this can mean waiting until spring for your first mowing. Some grasses, such as Zoysia grass, may need several months of growth to fully establish.
Much of the initial growth of new grass seedlings happens underground where you can't see it. New roots get grass firmly established, prepared for the seasons ahead, and positioned for strong, rapid growth when their peak season arrives. With proper timing, new grass seedlings compete well for light, water and nutrients and fight off lawn diseases and pests, including lawn weeds.
How to maximize the timing advantage. Even when you plant your grass seed at the best possible time, your lawn still needs help to thrive. Whether this is your first lawn or you’re the neighborhood expert, take some advise from turf professionals and get to know your grasses and soil before you start seeding. Follow through on best practices for preparing and planting, and don’t neglect traditional tasks, such as fall lawn care (we will talk about that next week), that will help keep your grass and soil healthy, well-nourished and ready to support new growth. Do your research to understand what’s in a bag of grass seed and the company behind the seed.