When To Plant Grass Seeds

Despite how it may look, planting grass is not as easy as scattering seeds along the soil and hoping the strong survive. To create a healthy, lush, and full lawn, you must prepare ahead of time and know what kind of grass seed to get.

There are two types of grass. Cool season grass is planted in the fall, while warm season grass is in the spring. Prepare the soil by checking the pH levels and removing debris. Plant the seed by evenly distributing it and maintain a constant moist atmosphere while it grows.

Purchasing the perfect seed that fits your climate and weather is essential to getting that new lawn, but not many people think about preparing the soil ahead of time. Unfortunately, not doing so can leave bald spots, disease-prone grass, and many weeds.

When to Plant Grass Seeds

A Gardener Sowing Grass Seeds

Like every other plant, grass seed has its best growing period to allow it to grow faster and more robust than in its off-season. However, most people don’t realize there are two types of grass seed: cool season grasses and warm season grasses. 

Cool Season Grass

Cool season grass consists of varieties like Kentucky bluegrass, perennial ryegrass, and tall fescue. They grow best in the late summer to early fall and thrive in northern climates. 

The best season to grow this kind of grass is in the fall, when the soil is still warm during the day but not the scorching hot that comes with the midday heat of summer. This allows for fast germination and the establishment of roots. 

The soil temperature for cool season grass should be between 50 and 60 degrees Fahrenheit, with the air temperatures roughly 60 to 75 degrees Fahrenheit. 

Although autumn is the best time to plant cool season grass, your location also determines what part of autumn to plant in. For example, the further north you are, the sooner your cool season grasses will need to be laid, while the more south you are requires planting to be done later in the season. 

However, as a general rule of thumb, plant the cool season grasses at least 45 days before the first fall frost since newly planted seeds need soil moisture and fall offers plenty of precipitation. Spring is the next best season if you cannot plant in the fall. With soil and air temperatures cool, you will also get good results.

Just be aware that the spring rains can cause the seeds to become overly wet, and weeds can outgrow your grass. The grass will also have less time to establish before the higher temperatures come, which can be problematic for germination and cause slow growth.

Warm Season Grass

The key to sowing warm-season grass is to avoid the scorching heat of summer but provide enough time before fall. With this in mind, spring is the best season to plant. Warm season grass consists of Bermudagrass, Bahiagrass, Zoysia grass, and Centipede grass, which grow best with soil temperatures of 65 to 70 degrees Fahrenheit and air temperatures of 80 degrees Fahrenheit.

With lots of showers and the warm climate of late spring and early summer, these kinds of seeds can grow efficiently before the too hot temperatures arrive.

Like the cool season grass, the exact timing of when to plant will depend on your location, with a general rule of 90 days before the first frost. This gives the grass time to establish since warm season grass goes dormant once temperatures drop to 55 degrees Fahrenheit. 

Factors to Consider

Location

Your location is essential to determine when to plant grass and what seed to grow. For example, if you are in a northern climate and purchase Bermudagrass, chances are it won’t survive, and vice versa if you live in a southern climate and buy a cool season grass. 

Warm climate grass needs to have most of the year above 55 degrees Fahrenheit as they tend to go dormant when temperatures dip that low. At the same time, cool-season grass can tolerate freezing temperatures but might get scorched in a hotter southern climate. 

Weather

When looking at what grass to purchase, you also want to consider the weather you get. Light rain helps germinate grass seeds, while heavy rains flood and kill them.

Don’t try to plant your grass when a storm is coming, as the seed will wash away. Instead, you want to ensure that the few days to a week after you plan to sow will be light rain or clear skies. Likewise, windy weather will blow the freshly placed seed away.

On top of this, you want to ensure you aren’t planting the grass in mud puddles after a heavy rain, as it can cause disease to grow.

How to Plant Grass

After choosing the best time of year to plant your desired grass, it’s time to prepare your site to plant the grass seed.

Site Preparation

Prepare the Site

You will want to begin by providing proper grading of the site to help water drain away and not pool. Next, you’ll want to slope the lawn away from buildings at a rate of 1 to 2 percent. Anything steeper will make the lawn dry out too quickly, and a smooth site allows water to pool and grow diseases in the grass.

If you are replanting an entire lawn, remove the old turf using a sod cutter (on Amazon) to lift the grass away from the roots. You can also spray the lawn with a herbicide, but be sure to use a non-invasive kind and follow the product’s instructions.

Preparing the Soil

A proper pH level in your soil will allow an optimal growth period and the grass to flourish. Generally, a good level to have is between 6.0 to 7.5. Alkaline soil can then be adjusted with elemental sulfur, and acidic soil can be fixed with lime.

After the pH is corrected, you want to fertilize the soil for optimal health levels to encourage healthy grass growth. 

If you have sandy or heavy soil, you will also need to adjust this, as compacted dirt can affect germination, and hardly anything grows in sand. You can improve the soil quality by removing rocks and adding compost for 2 to 4 inches deep before you begin planting. 

Planting the Seed

Once you have selected the best seed for your area, looked at the weather forecast, and prepared the site, it’s finally time to plant the grass! To do so, you want to distribute the seed evenly according to the package instructions. 

After the seed is down, use a rake to lightly work it into the soil for a depth of ¼ inch. Once it is raked, go over the area with a roller to aid the seed in meeting the earth adequately.

Keep the seeds and seedlings constantly moist for the first while. You want to water a newly seeded area about two to three times a day with a light spray to ensure it’s always moist. Once seedlings have begun to grow, you can transition to watering less frequently.

Maintaining Grass

Closeup of young green grass seeds that begin to grow on new top

Germination can take 5 to 21 days, depending on the type of grass you planted. After that, it will take another 4 to 10 weeks to establish and an entire season for a lawn to mature where foot traffic won’t damage it. 

Once the seedlings have reached roughly 1 inch high, monitor the lawn for any bald spots and reseed as needed.

After 3 inches, you can start mowing. Never cut more than a third of the grass in a single mowing; it will stress the grass and make it prone to disease and weeds. If you planted cool season seed in the fall, wait until the following spring to mow the lawn. 

For cool season lawns, you want to fertilize about four to eight weeks after the seed has germinated but no later than November. For warm season grass, you want to wait until the following spring to fertilize. After the initial fertilization, you will need to continue doing so four times a year.

Tips and Tricks

  • Prepare the soil ahead of time. Getting seed in the ground can take a bit longer, but you will appreciate the benefits later.
  • Remove any rocks or debris before planting.
  • Lay straw or hay over the seed to prevent birds from snacking and rain from washing it away.

Leave a Comment