When is the Best Time to Plant Grass Seed?

green grass

Your alarm clock goes off. You get up and make your morning coffee. 

It’s a beautiful sunny day, and, out on the porch, you enjoy the precious few moments of serenity before the work-day frenzy starts. And that’s when it happens — you see what has become the bane of your existence: the lawn.

You look around. As usual, your neighbor’s lawn is perfect and green. You wonder, yet again: where are you going wrong? 

The key to planting your lawn is this: timing and temperature. In fact, The US National Arboretum has divided the United States into different climate zones. 

The different climate zones are:

  • Cool/humid
  • Cool/arid
  • Warm/humid
  • Warm/arid 
  • Transition zone

Here is a USDA Plant Hardiness Zone Map:

seed grass
Source: planthardiness.ars.usda.gov

We at Clean Air Gardening love this map because you can enter your zip code and it will show the climate in your region. 

Remember: Temperature is crucial for choosing the best time to plant and deciding which grass seed will work best for your lawn. 

It’s not about the type of lawn soil you have, but about the type of grass. The catch is to know which ones are cool-season grasses and which are warm-season grasses

Cool-Season Grasses

These are seeds that are best planted in the spring and fall.

Why Is Fall the Best Season for Cool-Season Grasses?

Fall is the perfect time for cool-season grass seed because of soil temperature. 

In early fall, the soil is still warm from the summer months. The pleasant day temperatures and cool evenings make for perfect growing conditions for these types of seeds.

Use a thermometer to check your lawn’s temperature. The grass seeds will germinate best when the temperature is between 50°F and 65°F (10°C and 18°C). 

If your home is farther north, start planting your new lawn as soon as fall starts.  

For example, if you live in the Minnesota region, plant your lawn grass from mid-August to mid-September. On the other hand, if you are from a transition-zone climate — such as Arkansas — September to October is the perfect time for seeding your lawn.

Another reason for planting in the fall is a reduction in moisture. Your newly planted grass seed mix will need water, and as it rains a lot during this season, it makes for an excellent time for planting grass seed. There is no need for additional watering on your part. 

Here is a list of the best colder season seeds for your new grass lawn. 

Kentucky Bluegrass

KBG in sun shade mix with lower lack of water tolerance
Source: flickr.com

Kentucky Bluegrass has the greatest hardiness of all cool-season lawn grasses — it thrives in cold winters and moderate summers. In this climate, it will turn your existing lawn into a thick green carpet. 

This grass has a lower tolerance for heat and drought because of its shallow roots, so it’s most commonly found in the northern areas. Note that Kentucky Bluegrass (KBG) has rhizomatous growth, and it develops thatch easily. 

Fact: To prevent the grass from getting a disease, you’ll need to do dethatching every couple of years. 

KBG seeds germinate slowly, so plant them in the fall. Once spring and summer come, your lawn will be the envy of the whole neighborhood.

Perennial Ryegrass

seed sun lawn garden
Source: pexels.com

Perennial Ryegrass is another cool-season type. This grass type does especially well in the Pacific Northwest region, and it has become one of the most widely used grasses in that region — both on its own and in a mix with other grass seeds — because it produces high-quality forage

It’s related to Annual Ryegrass, the difference between them being that Annual Ryegrass is short-lived while Perennial Ryegrass comes back year-after-year.

Tall Fescue

new healthy turf green color lawn from seed
Source: flickr.com

Tall fescue is considered the best grass seed because it’s extremely adaptable and drought tolerant.

Fact: It can tolerate both sun and shade. 

It even has a capacity for self-repair. Plus, its root can reach up to 3 inches in the soil, so it won’t ask for too much work on your part.

Nevertheless, it’s a good idea to use lawn fertilizer and occasionally reseed your lawn to keep it in top shape. 

Pennington Smart Seed

If your home is in a region that has a mix of sun and shade, then Pennington Smart Seed should be your choice. Pennington Seed contains a mix of cool grasses that will thrive in partial shade areas. 

Lawns with Pennington smart seed mix can be very dense, and therefore have a high tolerance for:

  • Drought
  • Disease
  • Insects

Finally, this seed mix needs up to 30% less water than other cool-season seeds, so there isn’t much effort needed on your part to achieve that perfect, lush, no-bare-spots lawn in front of your home.

Warm-Season Grasses 

These seeds are best planted in summer.

Why Is Summer the Best Season for Warm-Season Grasses?

Warm-season grass should be sown when the soil temperature is in the 65°F to 70°F (18°c to 21°c) range. 

When you plant in late spring and early summer, the soil is warm enough and it can retain moisture for ideal warm-seed germination. 

Similar to the cool-season grass, the exact planting time varies by region. For example, in California, April to May is the perfect seed planting time. If you want a green lawn in Arkansas, wait until May to June. 

Zoysia Grass

seed sun and grass seed privacy policy
Source: flickr.com

If your lawn is in a warm region, look no further than Zoysia. This grass loves full sun and hates dense shade.

Note: It can tolerate light shade, unlike Bermudagrass. 

The reason Zoysia seed lawns look so good is their ability to tolerate:

  • High foot traffic
  • Heat
  • Drought

If you live in southern and transition zones, and your goal is to have a green lawn with little input, this grass seed is the solution. 


sq ft of new smart seed. Green lawns with no dense shade
Source: flickr.com

Bahiagrass is a grass seed that has outstanding heat and lack of water tolerance — because of its finer texture, improved density, and drought resistance. This makes this grass perfect for lawns in the southeastern US. 

Seed in spring to accelerate growth, and don’t worry about sunshade as this grass seed doesn’t need it.

Bermuda Grass

sq ft of lawn seed with no shade mix or high traffic
Source: flickr.com

Bermuda grass comes from tropical countries. It flourishes without water — compared with most other turfgrasses — and has extraordinary heat tolerance.

 Because of this, it’s considered a tough and resilient grass seed for lawns. 

However, the climate and soil in which it flourishes restrict the use of this grass seed — in colder areas it will turn brown and wither. 

Before you plant it, consider where you live and how high traffic your lawn is. 

Cool-Season Seed: Seed in Fall or Spring

Mowing Height
Soil Type
Traffic Tolerance
Kentucky Bluegrass 2 – 2½ inches Medium textured Light Full
Perennial Ryegrass 2 – 3 inches Acidic and Alkaline High Full
Tall Fescue Grass 2 – 3 inches Clay soil High Full

Warm-Season seed: Seed in Spring or Summer

Mowing Height
Soil Type
Traffic Tolerance
Zoysia Grass 1½ – 2 inches Slightly acidic High
Bahia Grass 2 – 2½ inches Sandy soil Moderate Full or moderate
Bermuda Grass 1½ – 2 inches Light textured High Full

Care for Your Lawn

Now that you’ve learned all about choosing the perfect seed for your yard, don’t forget about lawn care — you don’t want all that seeding effort to go to waste.

Check out our lawn equipment to keep your garden in top shape, and for some further reading take a look at ways to improve your lawn.

Featured image: flickr.com by heipei

lawn with text overlay When is the Best Time to Plant Grass Seed

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