May 2020 new lawn renovation new grass

How Long Does It Take For Grass to Grow?

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Written By: Mark Marino

a Massachusetts Core Applicator License holder and owner/operator of Lawn Phix,

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Late summer and early autumn is the perfect time of year to plant grass seed. Whether you overseed an existing lawn or completely renovate your lawn, this is prime time for cool-season grasses.

For cool-season grass, the cooler days and morning dew of early fall provide ideal conditions for grass seed and grass seedlings to thrive. And coming off the hot summer months, the soil temperatures are still warm enough to allow the cool-season grass seed to germinate quickly.

I know you’re excited as I am after planting grass seed and always ask:

How Long Does It Take For New Grass to Grow?

New grass takes about 7-10 days to grow.

However, germination and growth depend on many variables including the variety of grass, how often you water grass seed, and the temperature – specifically the soil temperature.

For example, Perennial Ryegrass can begin to germinate in as little as five days, while some Kentucky Bluegrass species take upwards of 30 days.

It’s a lot to take in, but if you want to learn more about how long it takes to grow grass…

Timing for Grass to Grow

Look, I know you want to know exactly how long it will take your new grass seed to sprout. However, there are a lot of variables when it comes to exactly how long it will take.

Some grass varieties take as little as a few days to germinate, others may take one to two weeks.

Watering and Temperature are also critical factors as well.

Let’s take a look at each factor and see how long you can expect for germination to take in your new lawn!

Grass Seeds and Speed of Growth

As you may suspect grass variety is a huge factor in the speed at which your lawn seed grows.

Fastest Growing Grass Seed Varieties

Pro Tip! No matter how long it takes for most of your grass to grow, you should not mow the lawn for at least 3-4 weeks after the seed is planted. You want to give it plenty of time to establish roots, and for all the late bloomers to catch up.

Fastest Growing Grass Seed Varieties

Type of GrassDays To GerminateSeason
Perennial Ryegrass7-10 DaysCool
Kentucky 31 Fescue7-14 DaysCool
Kentucky Bluegrass14-21 DaysCool
Bermuda Grass7-30 DaysWarm
Centipede Grass14-21 DaysWarm
Buffalograss14-30 DaysWarm

Grass seed variety is only the first aspect when it comes to the timing of how long grass takes to grow. So now let’s take a look at a couple of other major factors in how long it takes for grass to grow.

Temperature, water, and food.

Temperature’s Impact on How Long it Takes For Grass To Grow

One huge factor in the germination rates of grass is temperature – soil temperature especially.

The time of year in which you plant the grass seed, and the climate in which you live, will have a massive impact on how long it takes for grass to grow.

In fact, grass seed such as Bermuda grass seed actually requires a soil temperature of at least 70 degrees to begin germination. So if there are days in which the soil temperature is below 70 degrees, Bermuda grass seed can take up to 30 days to germinate, or as little as seven in proper temperatures.

The Optimum Temperatures for Grass Seed Germination

Seed VarietyOptimum Germination
Temperature in Fahrenheit
Bluegrass (All varieties)50-86°
Kentucky Bluegrass59-86°

These temperatures reflect average air temperature, whereas soil temperature may be closer to the high end. Most seeds sprout best in late spring, early summer, and fall.

If the temperatures are too hot, or too cold, seeds will likely not take root. Therefore you want to avoid any temperature extremes when establishing a new lawn, regardless of the seed variety.

The Closer to the optimal germination temperature, the faster your grass will grow.

Now let’s take a look at another factor.

Watering and It’s Impact on Seed Germination

Applying best practices to watering your grass seed and lawn will result in faster grass seed germination. But watering doesn’t only impact how fast your grass will grow, it can also affect how healthy your grass is too.

There are 3 general rules to practice when watering a lawn:

Water longer, less often

Please note that watering grass seed is vastly different than watering your established lawns. When watering grass seed, it’s super important to keep the seeds and soil as moist as possible until you see grass seedlings emerging from the soil. I like to water as long as possible without flooding or pooling any areas of the lawn, or possibly seed runoff and washout. I shoot for watering twice per day and 30-40 minutes in each zone. This keeps the grass seeds damp all day in my area.

However, watering your established lawn too frequently causes grass to grow quickly upward, but the vegetation becomes leggy and thin. Worst of all, the roots form to be conditioned for lots of regular watering. Meaning that if there ever is a drought, your lawn will burn more quickly.

Once your new grass seed has started to germinate, start skipping watering every other day.

Water at the right time of day

Early morning watering is the best for established lawns. This allows the lawn to absorb the water into the soil before evaporation from the sun and heat in the middle of the day.

Early in the morning will also allow the grass blades to dry. If you water too late, such as in the evenings or overnight, you’re inviting ideal conditions for lawn fungus and diseases.

Skip Watering when it rains

This is obvious, but to avoid over-watering, skip your watering schedule if it rains.

Following these three rules on watering will not only help your lawn grow faster, but thicker and greener. When it comes to your own lawn, what else could you wish for?

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Fertilizing Grass Seed & New Grass

When you’re seeding bare dirt, we recommend a few things to help speed up the grass seed germination.

  1. Starter fertilizer – Nitrogen for tow growth, Phosphorus to help root growth, and Potassium for all-around health of the plant
  2. Organic fertilizer – applying a slow-release nitrogen will provide a steady stream of food for your new grass as it begins to grow and establish its root system
  3. Lime – particularly for cool season grasses that are known for having acidic soil, neutralizing your soil pH will help the grass uptake more nutrients in the soil
  4. Humic Acid – optional, but we love soil amendments and micronutrients for our turf

If you’re overseeding an existing lawn, then a full application of starter fertilizer may be too much. The existing grass can take up most of that food and it can cause excessive growth in the turf. You could be left with grass upwards of eight inches or more before your new grass is ready to be mowed. Try a spoon-feeding approach.

Grass Seed Growth Timing – The Verdict

How long it takes for grass to grow will depend on the factors mentioned above. As a general rule, you will begin seeing results in about two weeks. But it can take up to a month to have grass become fully established.

If you are looking for a service to plant your new lawn for you check out the expert reviews on House Method before you hire.

Growing Grass FAQs

How often do you water new grass seed?

Every day. The key to growing grass from seed is keep the seed and soil moist. If the seeds become too dry for too long, you’ll never see proper seed germination.

How do I speed up grass seed germination?

By keeping the soil and grass seeds moist. You can cover the grass seed with peat moss to help retain moisture. Also, plant grass seed at the right time. Cool-season grass seeds thrive when the soil temperatures are in the 60-65 degree range. This make early fall the ideal time for planting grass seed.

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Author's Note: this piece has been updated for accuracy since its first publication on
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Author: Mark Marino
My name is Mark Marino, and I am the founder, owner, and operator of Lawn Phix. With a passion for lawn care and turf nutrition for over a decade, I've dedicated countless hours to correcting soil and perfecting lawns. Today, my expertise, backed by formal courses at UMass Extension Pesticide Education, allows me to offer top-tier lawn care services and advice. I am a fully licensed and insured lawn care applicator in Massachusetts, specializing in comprehensive turf nutrition, weed control, and lawn pest control. My license number is AL-0053865. Contact me at [email protected] or +1 (508) 500-8402.

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