How Long Does it Take Grass Seed to Grow?
Research shows that a well-planned grass seed lawn, coupled with thoughtful landscaping details, can increase a home’s resale value by anywhere between 12-15%.
With these benefits to homeowners, sowing grass seeds for a lush lawn becomes a no-brainer. However, what is less obvious is finding the perfect time to sow grass seeds and creating the right conditions for seed germination. Part of that is knowing how long it takes for grass seed to grow, but there are other considerations to consider as well.
In this post, you’ll learn the basics of how long it takes grass to grow, as well as everything else you need to know to help you plan the perfect lawn.
How Long Does It Take Grass To Grow?
Newly-planted seed relies on a variety of factors when it comes to growth speed. Depending on the grass species you plant, it generally takes anywhere from seven to 21 days for the first grass shoots to poke their way through the soil.
After the first sprouts emerge, grass can take up to four weeks to reach mowable length. Much depends on the mixture of seeds, having the proper growing conditions, and whether you’re planting warm-season or cool-season grass. For example, zoysia, a warm-season grass, will take three times as long to sprout as its warm-season compatriot, bermudagrass. Cool-season Kentucky bluegrass takes twice as long as tall fescue type grass seeds to germinate and sprout.
However, you can help create the ideal conditions by ensuring that you plant both cool-season and warm-season grass seeds well in advance of their peak growing seasons. The growing season is not the same as the planting season. For cool-season grasses, seeds must be planted in the fall so that they’re ready for the spring growth. Warm-season seeds call for a late-spring to early-summer planting, and the fastest-growing variety, bermudagrass, takes around 20-30 days to sprout.
The seven to 21 day window means that you should see your cool-season grasses begin to germinate later on in the spring, around late-May to early-June. The early to mid-summer season is when they’ll reach full growth, four weeks after this point. Warm-season grasses planted in the late-spring to early-summer will start shooting up right at the peak of the summer season, around mid- to late-July and early-August.
The initial planning and prep-work you put into planting your grass seed determine 90% of the success of germination. Your pre-planting decisions will also help you spend less time on lawn maintenance, once your seeds take root.
A few possible questions to consider when planning the perfect time to sow grass seeds:
- What are your site’s or property’s conditions? Evaluate areas of sun versus shade, areas of poor drainage, soil make-up (clay or sand?)
- Do you have enough topsoil or will you need to add more?
- Will you have enough time to devote to maintenance?
- How much foot traffic will your lawn receive? This matters because foot traffic affects your choice of seed. There are varieties of grass seeds you can choose that can withstand heavy foot traffic because they’re naturally heartier than others.
One of the most important questions you may face during the pre-planting stage is whether to use sod or seeding for lawn establishment. Seeding provides homeowners plenty of natural benefits including lower costs, the opportunity to plant specific varieties chosen by you, and less labor and time required for installation.
You can also benefit from the flexibility you gain when planting a mixture for specific site conditions. For example, most of your lawn may be exposed to sunlight, with some areas where trees provide shade. In this case, you can mix grass seed types and choose varieties for those that perform well in the shade. Then, you use another seed type that thrives in the sunlight and sow these in sun-exposed areas.
However, keep in mind that planting grass seeds means you have a limited amount of time for establishment. The latest you can sow grass seed for the greatest success of establishment is late summer to early fall. If you miss this window, your grass seeds may not germinate, or heavy rains can wash the seeds away early. It also takes a more extended period, up to two months, for seeded areas to reap grass so they’ll need to be restricted from use while baby grass shoots up.
Why Timing Matters When Planting Grass Seeds
Nature needs alignment to thrive, and your planting season needs to align with the seeds’ natural periods of growth. In the United States, there are a total of four to five zones, but timing becomes an issue for states located in the transition zone. These are zones in the mid- to the south-east of the country. Depending on where it falls, a state in this zone could experience warm/humid temperatures, cool/humid temperatures, and warm/arid temperatures.
States like California and Texas, for example, are divided into three different zones. This means that if you live in states located in the transition zone, both cool- and warm-season grasses could work for you.
U.S. Grass Climates: When To Plant, Based On Your State
U.S. grass climates can also help you make a better decision on what to plant. What grass types you decide to plant will then tell you when to start planting and how to stagger your seeding.
For example, if you live in Alabama, you’re part of zones 7-10. The National Turfgrass Evaluation Program (NTEP) chart says that the best type of grass would be either bermuda or zoysia. Since these are warm-season varieties, the best time to plant would be in the mid-to-late spring or through the early summer.
Bermuda grass and Zoysia grass are warm-season grasses, and their peak growth potential occurs during the warmer temperatures of late spring and early summer.
Cool-Season Grasses Love…
Cool-season grass seeds love early autumn. This is the point in time when the soil is still warm, but the daytime temperatures are still moderate enough to encourage fast germination. This means that late summer to early fall (mid-August to mid-October) is the best time to aim for planting.
However, if you miss the autumn window, you’ll have one more time in early March through April. Early spring is not as reliable as the autumn season because late-melting snows or early-spring rains can wash away seeds, keep soil cold, or give early weeds an advantage.
Pro-tip: If you’re planting in an area where there is going to be a lot of autumn leaf drop, err on the side of caution and plant in early August. Your newly-planted seeds will also benefit from having the soil all to themselves as there’s less competition from weeds.
Cool evening temperatures also speed up cool-season grass seed establishment. Ideal soil temperatures should be between 50°F to 65°F, which usually occurs when daytime temperatures are between 60°F and 75°F. You can use a convenient soil thermometer to make sure.
Cool-season grasses include:
- Kentucky Bluegrass
- Perennial Rye
- Tall or Fine Fescue
The farther north you are in the transition zone, the earlier you will have to plant. Transition-zone lawns in central or northern Arkansas, for example, should plant in September and October. However, Minnesotans in the Upper Midwest zone have from mid-August to mid-September to plant.
Warm-Season Grasses Need…
Like their name, warm-season grass seeds need warmer soil temperatures. They also thrive in warmer, and more humid or even arid climate zones in the U.S. Warm-season grasses include:
- Zoysia grass
- Bahia grass
The ideal soil temperature for warm-season grasses to germinate and thrive is 65°F to 70°F, with a daytime temperature of 80°F or more.
These temperatures dictate that the best time to plant warm-season grass varieties is in the late spring and early summer. However, transition zone states or those that are a little further north should act according to weather conditions on the ground. In California, for example, homeowners should aim for mid-April to mid-May. However, residents of central to southern Arkansas would do better to seed during the late-May through June period.
Rather than keeping the time-frame of late spring to early summer as a hard and fast rule, look for ideal weather conditions instead. You want the soil to be warm and moist (but not wet, as this could indicate a danger of rotting) and all danger of frost passes.
Making the Most Of Your Timing Advantage
Now, the big question about cool-season versus warm-season grass seed planting is, “When?” The amount of time you’ll need to plan ahead — and so leave enough time for proper germination — varies between these varieties.
Generally, cool-season grass seed must be installed at least 45 days before the first fall frost. That way, your seeds will have time to take advantage of the full autumn season, nestle in for the winter, and then emerge for the second season of growing during the spring. This level of forethought also means that your fall seeds will be well-watered, requiring less watering and maintenance from you when they sprout in the spring.
Warm-season grasses require at least a 90-day window before the first fall frost. These varieties rely on the sun’s natural boost and warm summer temperatures for a full season of active growing before going dormant. Once the soil temperature drops below 55°F, all growing activity in these seeds stops, so if you miss the planting season, hold off until the next year.
Timing matters immensely to a lush lawn because much of the growing “magic” happens underground, where you can’t see what’s happening. If you could capture the germination process, however, you would see new roots firmly establishing themselves from seeds. Robust root development allows for consistent growth, and optimal nutrient, light, and water intake, once the ideal weather conditions arrive.
Failing to plant cool- and warm-season grasses within their ideal growing seasons make lawns less able to thrive, more susceptible to rot, disease, damage, and brown, patchy, and even bare spots. What’s worse is that the soil supporting these seeds relies on strong, firm planting and root establishment to protect it from natural wind, water, and nutrient erosion.
At Nature’s Seed, we work with homeowners and lawn care specialists to develop and provide a superior grass seed planting strategy. Based on your lawn’s specific conditions and your personal goals for your lawn, Nature’s Seed gives you multiple options, planting aids, and best practices to ensure your seeds survive and progress to thrive! Contact Nature’s Seed to learn more about how timing and planning makes all the difference in planting.