Head's Up: This Is the Best Time to Plant Grass Seed

A vibrant, lush lawn is more than a nice place to sit or walk barefoot. A carpet of green in your home landscape ties together elements like trees, shrubs, and garden beds. A well-kept lawn can also help prevent soil erosion and runoff and helps cool the buildings it surrounds.

But sometimes, those beautiful lawns develop bare patches, or maybe you'd like to have grass in a section of your yard where it didn't grow before. Before you can enjoy that soft, full lawn, you'll need to figure out the best type of grass seed for your region as well as the best time to plant it.

What's the Best Time to Plant Grass Seed?

The best time to plant grass seed depends on the type of seed you're using. The type of seed to use will depend on your region and climate. Different grasses are suited to growing in different regions, so it's best to consult your local garden center, hardware store, or extension agency for seed selection and planting advice suited to where you live.

Warm-season grasses are adapted to flourish in the southern part of the country. During the spring, fall, and winter, these grasses go dormant, but they thrive and grow the most in hot summer weather.

Cool-season grasses grow best in cooler climates in the northern part of the country. They do most of their growing during spring and fall, sometimes going semi-dormant in very hot or dry summer weather. Kentucky Bluegrass, rough bluegrass, perennial ryegrass, tall fescue, fine fescues, and bentgrasses are some examples of cool-season grasses.

After you've figured out which type of grass seed to plant, you can decide when to plant. Plan to seed at the peak growing season for the grass you've chosen, keeping in mind that factors like frost dates will vary from region to region.

The Best Time to Plant Warm-Season Grass Seed

Because warm-season grasses thrive in higher temperatures, it's best to plant them in late spring to early summer as the weather is warming up. Time your planting until after the last frost date for your region has passed and the soil has begun to warm up.

You'll also want to make sure the warm-season grass seed you plant has at least 90 days to establish itself before temperatures drop and the plants go dormant in the fall. You'll get the best results over the long term if you give your lawn a full season to establish before the weather gets cold.

The Best Time to Plant Cool-Season Grass Seed

The best times of year to plant cool-season grass seed are the "shoulder seasons" of spring and fall. These varieties will grow best when the temperature is between 60 and 75 degrees—this will be in early fall in the northern regions and later in the southern parts of the country.

Fall is an ideal time to plant many cool-season varieties. Find out the first frost date for your region, and plan to seed at least 45 days before that to give the grass time to establish. It will experience another growth period when spring comes around.

You can also plant cool-season grasses in the spring, but spring weather can sometimes create cool, wet conditions that aren't ideal for seeding your lawn. If the soil is too cold and wet, weeds may outcompete your grass seed. Depending on the weather, your grass might not have much time to establish before the weather warms up and the plants grow more slowly.

How to Plant Grass Seed

Once you've figured out the best season to plant, it's time to seed your lawn.

1. First, you'll need to prepare the soil for planting. Remove any existing vegetation with a hand rake, then loosen and break up the top three or so inches of soil with a hoe or shovel, removing any rocks or debris. If you're seeding a large area, you may want to use a rototiller.
2. Rake the area until it's smooth and level, making sure there are no clumps. Water the soil well, then spread the seed.
3. If you're seeding just a small area, you can scatter the seed by hand. Try to seed thickly enough so you're planting about 16 seeds per square inch of soil—if the seeds are too spread out, weeds will find it easier to take over. For a larger area, you can use a seed spreader or hand hopper to dispense the seed evenly.
4. Finally, cover the seed with a very thin layer of mulch, such as straw, compost, or mushroom soil. This will protect the seeds from birds, wind, and rain and add fertility to your lawn.
5. Keep the area well-watered to help the seeds germinate—ideally, the top two inches of soil will stay moist until the new plantings are about three inches tall.
6. After this, water less often, roughly twice per week, and make sure the top several inches of soil gets a good soaking. It's best to water your lawn in the morning so that the moisture has time to burn off in the heat of the day, which helps keep diseases at bay.

While the grass is getting established, be sure not to walk on it. Once the lawn is roughly three inches tall, you can mow it for the first time. Adjust the mower so that only the top inch of the grass is trimmed off. After a half-dozen or so mowings, you can begin to fertilize your lawn.