When to Plant Grass Seed in Connecticut

House in the Post Hill Historic District, New London, Connecticut

Are you planting grass seed in Connecticut? Set your calendars: The sweet spot is between mid-August and mid-September. But is this the only time you can sow the seeds? Nope, there’s another window: mid-March through mid-May.

However, just knowing the dates is not enough. You need to consider other factors like temperature and soil conditions. Grass seeds might seem picky, but they really aren’t being difficult. What grass seeds are looking for is comfort and a perfect balance of moisture and warmth.

Best time to plant grass seed in Connecticut

The best grass seeds for Connecticut lawns include species like Kentucky bluegrass, tall fescue, fine fescue, and perennial ryegrass, which should be planted in the fall. But in the coastal areas, warm-season grasses like Zoysiagrass may also flourish and should be planted in spring.

When to plant cool-season grasses

growth of cool season grass
Infographic by Juan Rodriguez

The best time to sow cool-season grass seeds in Connecticut is between mid-August and mid-September when the air is cooler but the ground is still warm, usually around 50 to 65 degrees Fahrenheit.

How late can you plant grass seed in Connecticut? Aim to seed at least 45 days before the first frost sets in so your new grass has enough time to grow and establish a strong root system. 

Here are some specifics for each grass type and when you should plant them:

Kentucky bluegrass

  • Soil temperature should be between 59 and 86 degrees Fahrenheit.
  • Germinates slowly, taking 10 to 30 days to sprout.
  • Prefers full sun to light shade and well-drained soil.

Perennial ryegrass:

  • Soil temperature should be between 68 and 86 degrees Fahrenheit.
  • Germinates in 5 to 10 days under ideal conditions.
  • Tolerates a wide range of soil types and grows well in full sun to partial shade.

Fine fescue:

  • The optimal soil temperature range for germination is between 59 and 77 degrees Fahrenheit.
  • Germinates in 7 to 14 days.
  • Performs well in shaded areas and can tolerate poor soil conditions.

Tall fescue:

  • Soil temperature should be between 68 and 86 degrees Fahrenheit.
  • It takes 10 to 14 days to germinate.
  • Adapts to a variety of soil types and tolerates heat, drought, and shade better than other cool-season grasses.

If you happen to miss this window, an acceptable alternative would be early spring sowing from mid-March through mid-May, when the soil temperature is consistently above 50 to 55 degrees Fahrenheit.

Pro tip: The National Gardening Association has a very useful first and last frost dates chart, depending on your ZIP code. It can help you avoid sowing your seeds too late in the season and running into an early frost. 

When to plant warm-season grasses

growth of warm season grass
Infographic by Juan Rodriguez

While ideal for certain hotter regions, warm-season grasses are better adapted to the warmer, coastal areas of Connecticut in USDA hardiness zones 6 to 7. They are not really recommended for most of the state due to poor cold tolerance.

Here, Zoysiagrass may be a good choice, given its ability to handle foot traffic and some dry or saline conditions.

The right time to plant warm-season grass is late spring, typically from May to early June, when the air consistently records temperatures of 60 to 65 degrees Fahrenheit and the soil temperatures are above 50 degrees Fahrenheit.

Note: It’s important to remember that during Connecticut’s colder months, Zoysiagrass goes dormant and turns brown for about six months. It will also green up much later in spring than a cool-season grass type and can be slow to establish.

Best time to overseed in Connecticut

Spreading seed by hand over an area that has little to no grass

If your lawn appears thin or bare spots are beginning to creep in, overseeding can be a great way to improve its overall health and appearance.

Cool-season grass overseeding: For cool-season grass types, the best time for overseeding is the same as for new seeding: late summer to early fall (mid-August to mid-September). This period gives enough time for the new seeds to germinate and establish well before the freezing temperatures set in.

Warm-season grass overseeding: The best period for warm-season grass overseeding is between May and early June. Overseeding earlier than the recommended period will result in poor germination.

Note: If you need a more comprehensive guide on lawn care in Connecticut, including when to fertilize, aerate, dethatch, and so much more, you can check out our month-by-month Connecticut lawn care schedule.

FAQ about planting grass seed in Connecticut

What should you not do when planting grass seed?

If you’re just starting out and still learning how to plant grass seed, you should avoid these common mistakes:

  • Don’t plant the grass seed without first properly preparing the soil. Till, remove debris, and level the surface before you plant the grass seeds to ensure proper germination and growth.
  • Don’t forget to apply a starter fertilizer to provide essential nutrients for seedling growth.
  • Don’t mow the new grass too soon. You should wait until it reaches 3 to 4 inches tall before mowing.
  • Avoid using pre-emergent herbicides, as they can slow the seed germination. You should remove weeds by hand instead or use other non-toxic ways to kill weeds.

When is the best time to water my lawn in Connecticut?

In Connecticut, aim to water your lawn between 5 a.m. and 9 a.m. This is the best time to water your grass because the temperature is cooler, and the wind is usually calmer, so evaporation loss is minimal.

How much does it cost to seed a lawn in Connecticut?

The national average cost to seed a lawn typically ranges from $592 to $1,768, with an average cost of $1,122. It’s a bit cheaper in Connecticut, with prices usually falling between $0.09 and $0.18 per square foot, with most homeowners spending around $990.

Get help from a pro

The right timing, a bit of patience, and proper preparation can make all the difference in successfully planting grass seeds. If you feel overwhelmed by all these details, you don’t have to do this alone.

We can connect you with local lawn care professionals who know exactly when and what to plant and can manage the entire process for you. They can assess your lawn’s current condition, recommend the best grass seeds for your lawn, prepare the soil, sow the seeds, and even come back later to fertilize and mow your new grass.

Main Image Credit: Kenneth C. Zirkel | Wikimedia Commons | CC BY-SA 4.0

Adrian Nita

Adrian is a former marine navigation officer turned writer with more than four years of experience in the field. He loves writing about anything and everything related to lawn care and gardening. When he's not writing, you can find him working in his yard, constantly testing new lawn care techniques and products.