Best Time To Plant Grass Seed

As a homeowner, having the perfect lush green lawn is something you always aspire for. A big factor in having that perfect lawn is planting the right seeds at the right time. There are a lot of factors to consider while making this decision. Let’s take a look at everything you need to know about planting grass seeds for your lawn.

The grass variety and the temperature zone you live in are the major factors affecting sowing times. . For cool season grasses, the ideal sowing time is during the fall while for warm season grasses, the ideal sowing time is spring and early summer. For the former, you should sow the seeds at least 30 days before the first winter frost arrives, while for the latter, sowing should be at least 60 days before.

What is the Best Time to Plant Grass Seeds?

To achieve that perfect-looking healthy lawn, you have to respect and stick to the ideal growing schedule of the grass species and the climate of the area you live in. Because of this, there are some time frames within a year where growing new grass will give you more returns.

For example, generally, the lawns in the northern part of the US contain cool season grasses, Kentucky bluegrass, tall fescue, or perennial ryegrass some of the examples. Similarly, lawns in the southern part of the US generally contain warm-season grasses, St. Augustinegrass, Bermudagrass, and bahiagrass being some examples.

There is also the transition zone in the US where the climate is a combination of the southern and northern weather patterns. This region is also defined as the central-eastern portion of the country. In these regions, you can opt for both warm and cool season types of grass.

The following map gives a good idea about the division of different grass types based on the climate of the regions.

Growing the right type of grass during the right time of the year speeds up the germination process while also ensuring optimal grass root formation which leads to less waste and a thicker lawn.

The following table summarizes the right growing times for different grass species. Keep in mind that these are the suggested seeding seasons and they might differ slightly based on the local weather patterns.

Grass SpeciesPreferred Growing ClimateUSDA ZonesSuggested Planting Season
BahiagrassWarm season7-1Spring/summer
BentgrassCool season4-6Fall
BermudagrassWarm season7-10Spring/summer
BluegrassCool season2-6Fall
BuffalograssWarm season5-8Spring
CarpetgrassWarm season8-9Spring/summer
CentipedegrassWarm season7-10Spring/summer
Fescue (tall)Cool season4-7Fall
Fescue (creeping red)Cool season3-7Fall
Ryegrass (annual)Cool seasonAll USDA (seasonal)Fall
Ryegrass (perennial)Cool season3-6Fall
St. AugustineWarm season8-10Spring
ZoysiagrassWarm season5-10Spring

Why is Fall Considered to be the Best for Cool Season Grasses?

The reason why some grasses are categorized as the cool season is because of their growth cycles. Some grass species tend to go through their active growth during the cooler time periods of the year. If you plant the grass seeds just before the onset of this weather, then the seeds will have enough time to properly germinate and form stronger roots.

Cool season grass tends to germinate best when the soil temperature is between 50-60F and the air temperature is between the 60-75F range. During early fall or around august, when the soil is still farm after the summer but the air temperature starts to cool down a bit, especially during the evenings and the mornings, provides the perfect conditions for cool season grass seeds to germinate and establish a healthy root system.

These fall temperatures and conditions can arrive earlier if you live in more northern regions of the country. For example, in transition zones, the best time to plant cool season grass is between September to October. On the other hand, for people living in the upper Midwest, the ideal time to plant seeds starts from mid-august to mid-September.

 A good rule to follow is to plant your grass seeds about 45 days before the onset of the winter frost. This gives the seeds enough time to germinate and grow strong to be able to sustain the winter temperatures while also providing a second cool growing season in spring.

The fall season also receives more rainfall and consistent temperature compared to the summer and winter seasons which is an important factor for newly sown seeds.

The alternative sowing time for cool season grass is considered to be spring, but fall should be the preferred choice.

Why is Spring Considered to be the Best for Warm Season Grasses?

Warm season grasses tend to germinate best when the soil temperatures are between 65-70 and when the air temperature is above 80F. Planting the seeds during late spring and early summers provides the seeds with warm soil conditions and enough precipitation to keep the soil moist.

Similar to cool season grasses, the exact sowing times may vary based on the location you live in. For example, the best sowing time in California is between mid-April to mid-May. While in southern Arkansas, the best time would be between late May to June.

The ideal time to sow the seeds is when the winter frost has completely disappeared. Cold temperatures and wet soil are the worst combinations for germination.

What Should You Expect After Sowing the Grass Seeds?

After you have sown the grass seeds, the germination speeds can vary depending on the species of grass you are using and the climate in your region. Cool season Kentucky bluegrass can take a longer time to germinate when compared to tall fescue. Zoesia grass can take 2-3 times as long to germinate when compared to bermudagrass. On top of this, different seeds belonging to the same species can take slightly different times to germinate.

Generally, you can expect the seeds to germinate within 7-21 days. After germination, it can take a further 2-3 weeks for the grass to become long enough to mow. For the first few times you mow your garden, you shouldn’t cut the grass blades more than 1/3 of their size.

Step by Step Guide to Planting Grass Seeds

The first step in sowing grass seeds is to recognize the climate of the region you live in and select the right type of grass. Once you have made these decisions, you will need to prepare the ground for planting.

Grassroots while germinating are tender and don’t grow well in compact, dry soil. Begin by loosening and aerating the soil by digging up to a depth of 2-3 inches using a shovel or a trowel. This will also break up any larger soil lumps in the ground.

Also remove any existing dead plants, roots, and other invasive species using a hand cultivator. You can also use a hoe or a rototiller if you have to prepare a larger area.

Once this is done, use a seeding rake to even out the soil and to further break up any larger clumps of soil.

Lightly water the soil to make it damp but not wet. The water should be absorbed till at least 3-4 inches deep.

For smaller areas, you can spread the seeds by hand or use a handheld hopper spreader. Make sure the seeds are evenly spread on the surface. There should be about ¼-1/2 inch distance between the seeds (you can eyeball the distance). Spreading them too densely will make the grass outcompete one another.

Once you have laid down the seeds, cover them with a thin layer of mulch to protect them from birds, rain, and strong wind. You can straw, screened compost or mushroom soil as mulch. Although the mulch choice can also be determined by what nutrients are missing from your soil.

When is it Safe to Mow New Grass?

You should only start mowing the grass when it is taller than 3 inches. Make sure the blades of the mower are sharp otherwise they will tear through the grass blades. Also don’t cut the grass blades more than 1/3 of their length.

Should You Add Fertilizer to New Grass?

You should not add any chemical fertilizers while planting new grass. Fertilizers can burn the tender young grass blades and roots.

Alternatively, you can add some fresh mulch to boost the nutrients in your soil. You shouldn’t ideally add any chemical fertilizers till you have mowed your lawn at least 6-7 times.

How Often Should You Water Grass Seeds After Planting?

If you live in a warmer area or if the daily temperature rises above 80F, water the soil daily. On the other hand, if you live in a cooler area, you can water every other day. In the beginning, only provide enough water to make the top inch moist.

Once the seeds have germinated and they begin to show, reduce the watering frequency but start watering more deeply.

And once the grass has grown to about 2 inches, you can further reduce the watering frequency to 2-3 times a week. At this stage, provide enough water so that it reaches about 4-5 inches below ground.

Conclusion

Generally, warm season grasses should be sown during spring and early summer while cool season grasses should be sown during the fall. You should sow the seeds at least 30 days before the first winter frost in case of cool season grass and 60 days in case of warm season grasses.