When to Plant Grass Seed: Best Dates by Grass Type and City

Seed cool-season grass in late summer and warm-season grass in late spring. For tall fescue, Kentucky bluegrass, fine fescues and perennial ryegrass, that means mid-August to mid-September across the North and late August into early or mid-October in the transition zone and upper South. For common bermudagrass, seeded zoysia, centipedegrass, bahiagrass and buffalograss, it means waiting until the soil 4 inches (10 cm) down holds 65°F (18°C), which in most of the warm-season belt arrives in May or June.

The grass decides the season, so know which kind you are sowing before you pick a date. Cool-season grasses grow fastest at 60–75°F (16–24°C) and stall in summer heat; warm-season grasses grow fastest at 80–95°F (27–35°C) and need a summer of heat to establish. Sowing each just ahead of the weather it likes gives seedlings the longest possible run before their stress season arrives.

Grass seed planting dates by city

Each window below is the recommended seeding span for the city's region. Frost dates are there for reference only: lawn seeding follows soil temperature and the growing weather left after sowing, not a fixed count back from frost.

Frost dates are medians from NOAA 1991–2020 climate normals for each city's main weather station. Chicago and Detroit use Indiana's window, Boston and New York use Connecticut's, and Seattle uses western Oregon's.

For a town not listed, two cues set the dates. Cool-season seed needs 6 to 8 weeks of good growing weather after sowing, so finish while that much warmth is still ahead of you. Warm-season seed waits for 65°F (18°C) soil at the 4-inch (10 cm) depth, and it needs most of a summer afterward to harden before winter.

How to tell the soil is ready

A soil thermometer settles it. For warm-season seed, push it 4 inches (10 cm) into the ground and sow once readings sit at 65°F (18°C) or higher consistently and keep climbing; a single warm afternoon is not enough. For cool-season seed, read the soil about 1 inch (2.5 cm) down, where 50–70°F (10–21°C) gives the fastest germination. Once that shallow soil turns cold late in fall, seed stops germinating at all.

Notes on the table

Most lawns in Zones 4 and 5 are cool-season grass, so the Fargo, Minneapolis and Chicago rows send you there; native buffalograss is the main warm-season exception on dry, sunny sites. The Detroit, Kansas City, Boston and New York rows also point to cool-season grass, the usual seeded lawn in each. Nashville's row uses the window shared by Missouri, Maryland and the North Carolina piedmont.

West of the Cascades, fall timing is set by cooling weather and returning rain rather than by a late first frost. In western Oregon the best window runs August 15 to September 15, and seed sown after October 15 is rarely worth buying.

In California, cool-season grass does best sown in September and October, and seeded warm-season grasses go in from mid-April to mid-May. Where winters are as mild as Dallas's and Houston's, lawns are warm-season grass and cool-season seed has one job: overseeding a bermudagrass lawn for green winter color, covered in the overseeding section below.

Cool-season grass: why late summer wins

Late summer gives cool-season seed warm soil and cooling air at the same time, and that pairing is when it sprouts fastest. Germination peaks with soil about 1 inch (2.5 cm) down between 50°F and 70°F (10–21°C) and air running 60–85°F (16–29°C). Late August and September deliver both across most of the northern half of the country.

The timing pays off twice more. Seedlings get two cool growing seasons, the fall and the following spring, to build roots before their first summer. And crabgrass, the weed that smothers spring seedings, has finished sprouting for the year, so fall-sown grass meets far less competition.

Spring seeding as a second choice

Spring seeding of cool-season grass is hard to pull off. The seedlings come up alongside crabgrass, the leading cause of spring failures, and the frequent watering they need helps the crabgrass too; whatever survives then faces summer heat and drought on short roots. If bare soil cannot wait until August, seed as early as the ground allows. That means mid-February to early March in the North Carolina piedmont, late February through March in Georgia, March to early April in Maryland, and March or April in California. Indiana aims for early April, and western Oregon for early May to mid-June.

Dormant seeding over winter

In cold-winter regions, dormant seeding is often easier than a spring sowing: the seed goes down in winter, so it is already in place before the lawn could be sown. Spread seed on bare, prepared soil once it is colder than 40°F (4°C), which runs from early November to mid-March in Minnesota and from Thanksgiving to March in Indiana. Freezing and thawing work the seed into the soil without raking, and it sprouts as the ground warms in spring. Buy 10 to 20 percent extra seed to cover winter losses.

Warm-season grass: wait for 65°F soil

Warm-season seed needs the soil 4 inches (10 cm) down to hold 65°F (18°C) and keep rising, which arrives in mid to late spring across the South. Seed spread into colder soil sits idle while weeds germinate around it. Buffalograss shows the pattern plainly: it will not sprout until soil passes 55°F (13°C), however early you sow it.

The window also closes earlier than many people expect, because seedlings need most of a summer to toughen up before winter. Georgia stops seeding warm-season lawns by early to mid-August, and Colorado stops buffalograss and blue grama after July. Buffalograss sown between August 1 and October 1 often sprouts, then winterkills; sown from October through December, it behaves as a dormant seeding and comes up the next spring.

Which warm-season grasses grow from seed

Common bermudagrass, centipedegrass, bahiagrass, buffalograss and the zoysias 'Zenith' and 'Compadre' can all be seeded. St. Augustinegrass cannot, and hybrid bermudagrasses such as 'Tifway' and 'TifTuf' set sterile seed, so they go in as sod, sprigs or plugs during the same late-spring window. 'Celebration' bermudagrass is also planted only as sod or sprigs.

Plugs go 6 to 12 inches (15–30 cm) apart. Bermudagrass sprigs planted in May or June reach about 80 percent cover in 45 to 90 days. Zoysia sprigs take 60 to 120 days, so plant them early in the window.

Seeding windows by region

Recommended seeding calendars by region, which the city table follows, add local detail such as rainfall timing on the Pacific coast and the heat of the low desert.

Windows are the recommended seeding periods for each region's common lawn grasses; a dash means no standard seeding window for that grass type there.

Transition zone and the upper South

From Kansas City east through Nashville to Maryland, tall fescue is the usual seeded lawn, sown from late August into early October. In Missouri the single best week is the one either side of Labor Day. In Maryland and the North Carolina piedmont, zoysia and bermudagrass, where people choose them, go in from May into June or July.

In Georgia, tall fescue suits the Piedmont and gives out around Griffin; farther south it lasts only in shade or sheltered spots, so lawns there are warm-season grass.

Mountain West, desert and Gulf Coast

Along Colorado's Front Range and in northern Utah, buffalograss and blue grama, both native grasses, are the warm-season choices for low-water lawns. No warm-season lawn grass suits sites above about 7,000 feet (2,130 m), and buffalograss struggles above about 6,500 feet (1,980 m). It also does poorly in humid Georgia.

In the low desert of Arizona, bermudagrass is the best-adapted lawn, planted in the summer months; seed takes about a month to establish. Along the Gulf Coast, seed bermudagrass, bahiagrass or centipedegrass in spring or summer once the soil is warm, and plant St. Augustinegrass as sod or plugs. North Florida lawns seeded in late fall risk winter-kill, while south Florida can plant in any month.

Germination time and seeding rates

Ryegrass and tall fescue sprout within two weeks, while Kentucky bluegrass needs two to four weeks just to break the surface.

Germination days assume moist soil in the right season; follow the bag label where its rate differs.

Seeded zoysia goes down at 1 to 3 lb per 1,000 sq ft (5–15 g/m²) and bahiagrass at 3 to 8 lb (15–39 g/m²). Centipedegrass seed is so tiny that 1/4 to 1 lb (1–5 g/m²) covers the same area.

What changes the clock

Season shifts germination as much as species does. Tall fescue sown into warm fall soil in Georgia comes up in 5 to 10 days, while a spring seeding in Indiana takes 14 to 21; bluegrass mixes sown in spring take 18 to 28 days. Buffalograss speeds up to 7 to 21 days with warm soil and steady irrigation.

In a mix, the ryegrass or tall fescue shows first because bluegrass germinates 7 to 14 days later, so patchy early cover in a bluegrass blend is normal. Late in the season, the slow starter becomes the safe one: fall-sown seed that has not germinated by winter dies, except Kentucky bluegrass, which waits and comes up in spring.

Cheap mixes heavy in annual ryegrass look green fast and then die out within a year or two. Buy seed labeled with named cultivars, a high germination percentage and little weed seed. For shade, choose blends built on fine fescues such as red fescue, with rough bluegrass for fully shaded spots; where shade is too deep for even those, shade plants or a ground cover will outlast repeated reseeding.

How to seed a new lawn

Start preparing two to six weeks before your window opens, because weed control has to finish before the seed goes down.

1. Clear weeds and old turf. Spray glyphosate on actively growing weeds and worn turf about 2 weeks before seeding; it leaves nothing in the soil that stops grass seed. Most broadleaf weed killers need 4 to 6 weeks between spraying and seeding. Glyphosate kills any plant it touches, so follow the label and keep drift away from beds.
2. Test, loosen and firm the soil. Amend only as a soil test directs and work in a starter fertilizer, then rake smooth and firm the surface with a light roller until a footprint barely sinks.
3. Spread the seed in two passes. Sow half walking one way and the rest at right angles, so thin strips from one pass are covered by the other. Bulk out tiny centipede or bermuda seed with dry sand so it spreads evenly.
4. Rake lightly and roll. Work the seed into the top 1/8 to 1/4 inch (3–6 mm) of soil, leaving about 10 to 15 percent visible. Seed needs light to germinate, so never bury it under more than 1/2 inch (13 mm) of soil or 1/4 inch (6 mm) of compost. Rolling presses each seed against moist soil.
5. Mulch where the surface dries fast. On slopes and in full sun, a thin layer of straw or 1/8 to 1/4 inch (3–6 mm) of fine mulch holds moisture; any deeper and seedlings struggle to emerge.
6. Water the same day. Soak the seedbed right after seeding, then switch to the light, frequent schedule described in the last section.

Overseeding an existing lawn

Overseed a thin cool-season lawn in the same late-summer window as a new one. It makes sense while the lawn is thin but still mostly the grass you want; if it is dead, weedy or worn out over most of the area, kill it and start over with the steps above.

Mow to 1 to 1.5 inches (2.5–4 cm), then core aerate or power rake until bare soil shows between the plants, because seed resting on thatch rarely roots. Scale the seed to the loss: if half a tall fescue lawn has thinned, use half of a 6 lb rate, or 3 lb per 1,000 sq ft (15 g/m²). Leave topsoil and sand off the overseeded lawn.

Winter color on warm-season lawns

Bermudagrass lawns in the South and Southwest can be overseeded with perennial ryegrass or rough bluegrass for a green winter. In the Arizona low desert, October is ideal, when days run 80–85°F (27–29°C) and nights drop to about 55°F (13°C); in Georgia the window stretches from September through November. Sow too early and the still-active bermuda smothers the ryegrass; sow too late and frost catches the seedlings.

Skip overseeding in a new bermuda lawn's first winter, and overseed only bermuda that has had about 100 days of growth. Leave St. Augustinegrass and zoysia alone, and keep annual ryegrass to bermuda lawns only, never in a permanent seed mix. Done carelessly, overseeding can weaken the warm-season grass underneath, so treat it as optional. If a sunny slope keeps failing as lawn, a meadow sown at the right time for wildflower seed is worth considering instead.

Seeding too early, too late or into frost

For cool-season grass, seeding late is the more common and more costly mistake. Finish early enough that seedlings get 6 to 8 weeks of mild growing weather to root before the cold. Seed sown later risks winter injury, and once the soil turns cold it does not germinate at all. When days shorten to under about 10 hours of light, no lawn grass grows, and November killing frosts can damage young seedlings.

If you are a week or two late, more seed helps: in western Oregon, add 2 lb per 1,000 sq ft (about 10 g/m²) for each week past mid-September, and stop after October 15. Any later than that, hold the seed for dormant seeding in a cold-winter area or for the earliest possible spring sowing instead of throwing it at cold soil.

Seeding warm-season grass too early only wastes seed and gives weeds a head start, so a soil thermometer reading saves money. Sowing it too late is the real danger: seedlings that sprout in late summer go into winter too small to survive it, which is why seeding stops after July in Colorado and by early to mid-August in Georgia.

Watering, first mowing and the first season

New seed lives or dies by moisture for its first three weeks. Soak the bed 4 to 6 inches (10–15 cm) deep after sowing. For the next 2 to 3 weeks, keep the top 1 to 2 inches (2.5–5 cm) moist but not soggy; light waterings, one to four times a day, do it. Once seedlings reach 1/2 to 1 inch (13–25 mm), water less often and more deeply so roots follow the water down. Overwatering rots seed or washes it away, and evening watering in summer invites disease such as pythium.

Make the first cut as soon as the first blades reach about 2 inches (5 cm), removing no more than a third of their height. Over the next 3 or 4 mowings, raise the mower to its normal height. Tall fescue sown in fall can be ready in 2 to 3 weeks, a mid-August seeding in western Oregon in about 3, and most lawns within 4 to 6 weeks. Use a light mower on dry grass, since wet seedlings pull out and the wheels rut soft soil.

Keep people and pets off the new grass for at least a month after it comes up, or until it has been mowed twice. Feed with a light nitrogen application about 6 weeks after germination. Hold off on broadleaf weed killers until the lawn has been mowed at least 3 times, roughly 45 days after germination, and follow the crabgrass preventer timing in the warning above.

A seeded lawn looks finished within weeks but takes nearly a full growing season to toughen into turf that handles heavy use and summer stress. To line up the rest of the year's garden jobs around your seeding window, use Sow's garden calendar.