When to Plant Grass Seed

With articles on the best time to lay sod and the best time to plant grass plugs, Sod University also tackles the discussion of the best time to plant grass seed. When it comes to this landscape project, a couple of different factors come into play. Is it warm season or cool season grass seed? Where are you geographically located? What is the purpose of the seeding project? Consult your local land-grant university for specific information on when to plant grass seed in the exact area you are located.

Generally speaking, you can plant grass seed any time of the year, but fall is the best time to seed a lawn with a cool season turfgrass variety. Spring is the best time to plant warm season turfgrass seed. Cool season varieties of grass seed include tall fescue seed, ryegrass seed or even Kentucky bluegrass seed. Warm season varieties can include grasses like bermuda grass, zoysia or St. Augustine. It should be noted, though, that there’s no such thing as St. Augustine seed. Read below to find out how you can successfully plant grass seed throughout different times of the year.

How to Plant Grass Seed in the Fall

Cool Season Grass Seed

Overall, fall is the best time to seed or overseed with a cool season variety no matter where you are located in the country. If you are above the transition zone, the best time slots are around the weeks between August 15th–October 1st. As you get farther south towards the transition zone, your window of opportunity expands a little more and you can seed during the weeks of Labor Day through the end of October instead.

If you follow these dates, your grass seed will germinate properly. You also won’t have as much weed pressure as you would during the spring or summer because of the killing freeze that will arrive a few months later.

This timeframe applies to seeding your entire lawn with grass seed or overseeding a warm season grass with a cool season grass. During the fall, homeowners will sometimes overseed their warm season bermuda grass with a cool season grass like ryegrass, for example, to keep it green during the winter once their bermuda grass goes dormant. Learn more about this in How to Keep Your Lawn Green During the Winter.

Warm Season Grass Seed

Fall is definitely not the best time to plant warm season grass seed because it may not have a lot of time to germinate before the onset of winter temperatures. Even if it does have time to germinate, it still may be a little too weak going into the winter and might be susceptible for winterkill and winter damage.

How to Plant Grass Seed in the Winter

It is not recommended that you plant grass seed during the winter months for either warm or cool season grass seed. The chances of it sticking around and not washing away during the winter are pretty low. The spring and fall seasons, in comparison, will guarantee the most success with seeding projects.

How to Plant Grass Seed in the Spring

Cool Season Grass Seed

Spring is the second best time to plant grass seed for cool season varieties. The best time to plant cool season grass seed during this season is somewhere between the weeks of April 1st–May 15th. This will give you a few weeks to get your seed to pop up from the surface of the soil. March is still pretty cold in the cooler areas up North.

You can expect more weed pressure in the spring, though, because weeds like crabgrass will be germinating around this same time. You also won’t want to overseed a warm season turfgrass with a cool season turfgrass in the spring.

Warm Season Grass Seed

Spring is the best time to plant warm season grass seed. The timeframe that guarantees the most success with a warm season turfgrass variety is around the month of May if you are located in northern areas of Georgia or North Carolina. As you get farther south, the window of opportunity expands.

Be sure to really irrigate your grass seed at this time as the proper amounts of irrigation will help it germinate before the onset of summer heat. The grass will fill in rapidly through the heat of the summer in July, August and early September.

A popular warm season variety homeowners love is centipede grass, which should stay within the May timeframe if you plan on seeding it. Centipede seed planted in May will really pop before it gets too hot, so this gives you time to have the proper irrigation and help it grow in beforehand.

How to Plant Grass Seed in the Summer

Cool Season Grass Seed

It is not recommended that you plant cool season grass seed at this time because the grass will be dormant. It will not be worth your time and effort unless you are located really far up North. Sod University suggests blocking out the dates of June–early August before doing this.

Warm Season Grass Seed

The summer is not ideal for warm season grass seed either because of the extreme heat. You would have to spend a lot of time and money irrigating it. It is possible to do this in the summer, but you will need to spend a lot more time and money on proper amounts of irrigation.

Recommended Products for Grass Seed Projects

Take a look at some of our products for your seeding project coming up. The Lawnifi® New Lawn Starter Box, which contains three bottles of Lawnifi product, is the best fertilizer for new seed. It contains everything newly seeded lawns need to establish thick, healthy grass including two bottles of Grow for improved soil health and one bottle of Maintain to feed the lawn. This fertilizer box will give your grass the nutrients it needs during establishment.

In summary, you can plant grass seed anytime during the year. However, fall is the best time to plant grass seed or overseed with a cool season grass seed while spring is the best time to plant warm season grass seed. The winter is not recommended for either cool or warm season grasses due to the harsh, cooler temperatures. This is partially due to the risk of seed being washed away or newly germinating seed heads experiencing winterkill. You can seed warm season grass in the summer, but you must be fully prepared to spend a lot of time and money irrigating it. It is not recommended you conduct seeding projects with cool season turfgrass in the summer because the grass will likely be dormant.