When is the Best Time to Plant Grass Seed?

person planting grass seeds

Is your lawn thinning or littered with bare spots? Laying down grass seed is one way to get your lawn lush and green again. While you can plant grass seed throughout the year, planting during certain times of the year will bring you a higher chance of success. This guide can help you figure out the best time to plant grass seed in your area.

The Best Time to Plant Grass Seed

The best time of year to plant your grass heavily depends on the type of grass you’re trying to grow and where you live. Do you live in a cool-season grass area, a warm-season grass area, or the transition zone, where both types of grass can thrive? Check out this map to see what type of grass seed is typically grown in your region.

A picture showing the distribution of various grasses
Photo Credit: Juan Rodriguez

Generally, you’ll want to plant grass seed during your turf’s active growing season if you want quick results and a higher chance of success.

The Best Time to Plant Cool-Season Grass Seed

A picture showing growth of cool season grass round the year
Photo Credit: Juan Rodriguez

If you live in the northern part of the U.S., you most likely have cool-season turf in your yard. Cool-season grasses like Kentucky bluegrass, fine fescues, tall fescue, bentgrasses, and perennial ryegrass grow most vigorously during the cooler seasons of fall and spring. They slow down their growth during summer and winter.

Cool-season grass seeds sprout best when the soil is around 50 to 60 degrees Fahrenheit (when the air temperature is about 60 to 75 degrees). As such, the ideal time to plant cool-season grass seed is late summer or early fall. Your window of opportunity changes depending on how close you are to the transition zone:

  • Above the transition zone, homeowners can seed their lawns as early as Aug. 15 but no later than Oct. 1.
  • If you’re closer to or are in the transition zone, you should wait a bit longer before seeding. You can seed from around Labor Day to late October.

Planting as early as the last weeks of summer gives your grass time to establish before winter sets in. In fact, the latest you can plant your grass seed is 45 days before the estimated date of the first frost. Any later than that can kill tender seedlings and prevent un-sprouted grass seeds from germinating until spring.

Late summer and early fall are good times to plant cool-season grass seed for other reasons, too. Here are some of them:

  • Perfect temperatures. The warm soil from the summer months will foster germination, but it won’t be scorching hot. The air and soil temperatures will only get cooler, too, which is perfect for cool-season turfgrasses.
  • Frequent rain. It tends to rain more during the last few weeks of summer up into fall. Frequent rain helps keep your grass seeds moist, which is key to fast and successful germination.
  • Less stress on the grass. Cool-season grasses have better cold tolerance than they do heat tolerance. Your new grass will survive winter easier than the scorching summer heat that follows a spring planting season. It’ll save money for you too, as you won’t need to irrigate as much just to keep your new grass alive.
  • Less weed pressure. While winter annuals and other weeds can still compete with your grass, the weed pressure isn’t as strong as in spring.

If for some reason you can’t plant grass seed during this time, then the second-best time to plant cool-season grass seed is in the spring. You just have to wait until the soil warms up to 50 to 60 degrees Fahrenheit before planting. Typically, this means planting from April 1 to May 15, but you may have to wait longer the further north you live.

Spring has similar weather and temperatures to fall, which is why it’s the second-best time to plant cool-season turfgrasses. However, it brings its own set of problems:

  • More weed pressure. Spring is prime weed seed germination time. Your new grass will have to compete with them, especially those that sprout much earlier. 
  • Herbicide interference. Many weed killers require a one-month waiting period before laying down new seeds. If you’re trying to get ahead of crabgrass, then it’s even worse: You’ll have to wait an average of four months after applying crabgrass preventer to plant your seeds.
  • Excess moisture. The combination of spring showers and late-melting snow can make the soil overly wet. This can lead to seed displacement, lawn disease, and even seed rot.
  • More stress on the grass. Your newly planted grass will have to contend with the summer heat soon after establishment, which can stress it out. Cool-season grass generally has poor heat tolerance. And that’s if you plant it in time; if you plant too late, it may not be established before summer.

The Best Time to Plant Warm-Season Grass Seed

Photo Credit: Juan Rodriguez

Homeowners in southern states and those in the southern reaches of the transition zone typically have warm-season grass growing on their lawns. Warm-season turf, like Bermudagrass, bahiagrass, buffalograss, centipedegrass, Zoysiagrass, and St. Augustinegrass, grow best during the summer and will go dormant when the temperatures start to drop.

Warm-season grass germinates best when the soil temperature is in the 65- to 75-degree range, translating to a daytime air temperature of about 80 degrees Fahrenheit. So, you want to plant warm-season grass seed during late spring or early summer. Your window of opportunity widens the further south you go, where the temperatures stay relatively consistent year- round.

Note: Homeowners living near or in the transition zone may need to wait until May to plant their warm-season grass because of the risk of frost. However, they should plant no later than 90 days before the predicted date of the first frost.

Late spring to early summer are the best times to plant warm-season grass because of the following reasons:

  • Ample time for grass to establish. Planting warm-season grass as early as late spring will give it time to establish so it can endure the summer heat and prepare for winter dormancy. Established warm-season grass has poor cold tolerance; imagine how the seedlings would fare when faced with cold weather.
  • Warm temperatures. Late spring and early summer are warm, but not scorching hot. Planting too late into summer will make your tender seedlings face the heat of summer before they have a chance to establish. While warm-season grasses tolerate heat very well, they need time to grow strong roots to survive the heat.
  • Rain. This time period still has a fair amount of rain, which helps your seedlings stay moist. Drying out is the enemy of germination.

While late spring and early summer are the best times to plant warm-season grass, you can also plant your seeds in early spring or late fall if your area has mild winters.

Tips for Planting Grass Seeds

Knowing the best time to plant grass is an important part of successfully growing new turf, but it’s not the only thing to keep in mind. Weather and lawn prep also help a lot to ensure successful germination. Here are some tips for planting grass seeds:

Check the Weather

Always check the weather conditions before you plant your grass. If clear skies or light rain are predicted, then you’re good to go.

However, you should hold off on seeding your lawn if the weather forecast predicts a coming storm or heavy rain in the next few days. Here are some reasons why anything more than a light shower is bad for planting grass seed:

  • Muddy soil. While we want our soil moist, we don’t want it soaking and muddy. Planting grass when there’s too much soil moisture can invite fungal diseases to your new lawn. In the worst-case scenario, your seeds may rot in the ground.
  • Seed displacement. Heavy rain can wash away the seeds after you’ve laid them down.

You also should avoid planting grass seeds when it’s windy outside so the seeds don’t get blown away while you spread them. Strong wind also can displace grass seed that’s already been laid down.

Stop Using Herbicide

If you plan to plant grass, you should mind your herbicide use. In most cases, you should stop using herbicides at least a month before you plant your grass seeds. However, some herbicides require a longer period of time between the last use and planting. 

For example, homeowners who treated their lawns for crabgrass have to wait an average of four months before seeding their lawns.

If you have to deal with weeds, then consider hand-pulling them instead.

Level Your Lawn

While planting grass on a slope isn’t impossible, it’s certainly more difficult. If you don’t want the extra trouble, you should level your lawn before planting. Fill in valleys with a mix of sand, topsoil, and compost. You can use a rake to level the soil. Any rocks and debris should be removed, too.

Dethatch Your Lawn

Infographic by Juan Rodriguez

Thatch is a spongy layer of living and dead plant matter that lies above the soil and below the grass. Excess thatch can house pests and foster lawn diseases, so it’s important to remove it before planting your grass seeds. Dethatching also helps ensure good seed-to-soil contact.

You can give your lawn a good raking to help remove thatch DIY. You may need a specialty tool like a dethatcher or a verticutter if the thatch layer is too thick.

Aerate Your Lawn

a illustraton of aeration
Infographic by Juan Rodriguez

The root system of grass seedlings isn’t strong enough to break through tough, compacted soil. Lawn aeration can take care of your soil compaction problems. It also helps control weeds and mitigates drought stress, both of which are dangerous for new seedlings. 

If you want to save money, you can aerate your lawn DIY with garden forks or aerator shoes instead of hiring a lawn care company or renting a core aerator machine. 

Test Your Soil

Instead of guessing what nutrients and amendments your lawn needs, you can conduct a soil test. The soil test results will tell you exactly what’s up with your soil and if there are problems that need to be fixed. 

If needed, you should fix your soil’s pH levels and add the proper fertilizer to address nutrient deficiencies before planting your grass.

Use a Starter Fertilizer

There are special fertilizers formulated for growing grass, which can give your new turfgrass the boost it needs to grow vigorously. Check if your state or county has any restrictions on fertilizer, though, and be careful not to over-fertilize. Too much starter fertilizer can backfire on you and harm your growing turf instead.

If you’re going to apply fertilizer, use it before spreading grass seed. This makes it less likely for the fertilizer to burn the young roots.

Spread Seeds Evenly

how to spread fertilizer graphic
Infographic by Juan Rodriguez

Nobody wants a patchy, uneven lawn. To make sure your grass seeds are spread evenly, you can use a seed or fertilizer spreader.

You’ll want to spread the grass seed throughout your lawn in two passes. First, spread half of the grass seed from north to south. Then, spread east to west.

After spreading the seeds, give the seeded areas a pass with the back of a rake to encourage good seed-to-soil contact.

Cover with Mulch

We recommend covering your newly planted grass seed with a thin layer of mulch before you first water your lawn. The mulch will help prevent water from evaporating, which keeps your seeds moist. If the seeds and seedlings dry out, they will die. Straw or peat moss work best for this.

Mulch also helps protect your seeds from pests that can eat the seeds.

Water After Planting

After laying down your seeds and your mulch, you should water your lawn for five to 10 minutes. You want to make the top 2 inches of soil moist after planting your grass seed. Be careful not to overwater, though.

How to Care for New Grass

newly planted grass seeds in a lawn
Photo Credit: Backyard Productions / Canva Pro / License

Whether you’re patching up an existing lawn or seeding a new one, there are a few precautions you must take before you can confidently say your newly-seeded grass is ready to enjoy. Like any growing plant, your grass seedlings are delicate and need more TLC than an established lawn. Here are some things to keep in mind as your new grass is growing:

  • Water Regularly
  • Mow at the Right Time
  • Keep Off the Grass

You can check our article on How to Plant Grass Seed for a more in-depth look at caring for new grass.

Water Regularly

Your newly planted grass will need a lot of water to sprout quickly and grow fast. However, you should be careful not to overwater.

Generally, you should water new grass seeds two to three times a day for five to 10 minutes. You should follow this watering schedule for one to two weeks until the seeds have sprouted. You want to keep the top 1.5 inches of the soil moist during this stage.

You may need to water less often if the temperatures are cooler, and more often if they are hotter.

If you want to learn more about watering new grass, then you can read our article on How Often to Water Grass Seed.

Mow at the Right Time

You want to wait for your new grass to be tall enough before you even think about mowing it. Generally, you want to wait until the grass is 3 to 4 inches tall before you bust out your lawn mower.

It can take anywhere between a few weeks to a few months before you can mow your lawn for the first time. Some grasses, like Zoysia, grow much slower and will take longer to reach the 3- to 4-inch mark.

Keep in mind that grass in shaded areas grows slower, so you will have to wait a longer time before you can mow it.

Keep Off the Grass

While your grass is growing, keep foot traffic to a minimum. That means no stepping on the grass and no playtime in the yard for at least a month. And you definitely don’t want your dog or cat using your brand-new grass as a bathroom. 

FAQs About the Best Time to Plant Grass

What Grass Germinates the Fastest?

Annual and perennial ryegrass seeds can germinate in as little as five days. Bermudagrass and buffalograss are tied for second place, which can germinate in as little as a week.

Can You Plant Grass Seeds in Winter?

Yes, you actually can plant grass seeds in winter if you live in a state that gets snow. This act is called dormant seeding, and it’s typically done in late fall or early winter when the temperatures are too cold for germination but before the ground freezes. The snow protects the seeds until they’re ready to germinate. It has its own benefits, such as less competition from weeds. 

However, don’t expect your grass to grow until spring next year when the temperatures warm up if you decide to dormant seed. You should also only dormant seed with cool-season grass.

When Should You Overseed Your Warm-Season Lawn For the Winter?

You should overseed your warm-season lawn with cool-season grass in the fall. Why? Overseeding with cool-season grass will give your warm-season lawn some temporary color during the winter months.

Hire a Pro for a Green Lawn

Planting grass seed at the proper time can get you the lush lawn of your dreams. But planting at the correct time isn’t the only factor that affects how successful your new lawn will be. You also have to care for it properly, stay on top of weed control, and mow at the right time.

Why not hire a lawn care pro to do the dirty work for you? LawnStarter can connect you with local lawn care companies that have the knowledge, skill, and experience to grow you a new lawn. Hire a professional lawn care service through LawnStarter today.

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Main Image Credit: schulzie / Canva Pro / License

Janine Caayao

Janine Caayao

Janine Caayao has always been fascinated with growing plants, from fruits and veggies to bonsai trees and orchids. Now, she’s interested in urban gardening with her family. She loves finding new tips and tricks to keep their plants thriving.