There are a number of factors that determine how long it will take grass seed to grow. From the variety of seeds you choose to sow through to the soil conditions and weather.
This guide will help you understand how long does it take grass seed to grow? We will share expert advice covering the different factors involved, and share how you can help your grass seed to grow better, faster, and stronger.
How Long Does Grass Take To Germinate
The first factor in determining how quickly grass seed will grow is the type of seed you purchase for your lawn. Different varieties of grass seed will germinate and grow at different rates.
Under ideal circumstances, it takes between 7 and 30 days for grass seed to germinate, depending on the variety.
Here are some popular grass germination rates:
- Perennial Ryegrass germinates in 5 to 7 days
- Annual Ryegrass germinates in 5 to 10 days
- Kentucky Bluegrass germinates in 10 to 21 days
- Red Fescue germinates in 12 to 22 days
- Zoysia Grass germinates in 14 to 21 days
- Bentgrass germinates in 14 days
Of course, grass seed type is just one the factors so let’s run through what else we need to understand to confirm how long it takes for grass seed to grow.
How Fast Does Grass Grow
So, how fast does grass grow? Well it really depends depending on the variety.
Each strain will grow at different rates and begin growth at different air and ground temperatures.
As a general rule, you will see 1-3 cm of growth per week during the season. With higher rates of growth during the peak growing condition and less at the beginning and end of the summer.
Once temperatures reach around 6-8 degrees (45 Fahrenheit) in early winter grass growth slows to the point of not requiring mowing. Then in spring, it will begin growing again when temperatures reach around 12 degrees (55 Fahrenheit), allowing for the ground to warm.
How Long Does It Take Grass Seed To Grow 2 inches
Let’s do the math to make an estimated average growth rate from seed to a blade of grass reaching 2″ tall:
- A germination rate of 5-22 days
- A growth rate of 1-3 cm per week
So we can take an average based on our sample of grass varieties identified at the beginning o this article to simulate an average growth rate from germination to 2″ tall
So, 12 days of germination and 2 cm (0,8 inches) of growth per week, to estimate grass will take 31 days on average to grow 2 inches (4.8cm) from seed.
How Much Grass Seed Do I Need
As a general guide, when creating a new lawn, it takes roughly two to three pounds of grass seed for every 1,000 square feet of soil. At the most, you may need to use up to five pounds (2.3kg) of seed per every 1,000 square feet (92 square metres).
Keep in mind that if you are reseeding your lawn and not creating an entirely new lawn, you will only need about half the amount of seed. Some varieties of grass will require even less seed for this purpose.
You will want to check the label of your grass seed for specifics related to the type of grass seed you are using.
Can You Put Down Too Much Grass Seed
Although it seems like more grass seed would mean a thicker and more lush lawn, the truth is that putting down too much seed will not give you the desired effect. In fact, putting down too much seed may have the opposite effect.
Germinating grass seed are prone to the same competition problems as all vegetation.
In every square foot of soil, there is a finite amount of space, nutrients, water, and sunlight that can be used or shared.
There’s no doubt under the right conditions the seed will germinate. But there will be a race to survive with many seeds being choked out, or fail to grow and simply die off.
It won’t be the case that the weak will all die and the strong will produce a beautiful lawn. It’s more likely all of the seed will suffer resulting in a weak lawn with young blades of grass wide open to disease, or simply be too weak to survive the stress of variable weather conditions.
Of course, you should always check the sowing instructions for the seed distribution density on the grass seed packaging. They will have been tested for optimum growth so take advantage of the work the producers have done on our behalf, don’t guess.
If in doubt use a thin spread of seeds, as you can always sow a second layer if the grass loos thinner that you expected.
How To Germinate Grass Seed
You can always throw grass seed out into your lawn or soil and hope for the best. A lot of seed will likely germinate and grow by its own volition. But there is a lot you can do to improve the germination rate so that you don’t waste money or seed. You’ll get the best lawn for the dollars you spend.
- Prepare the soil. If you are starting a new lawn, till the soil four to six inches deep and lightly rake it until it is smooth.
- Sow the seeds at the right time of year.
- Water your grass seed frequently to keep the soil moist until the seed is well-established.
- If necessary, cover the seed with a light layer of scattered straw or screening to keep the seeds from being eaten or blown away.
- Monitor your lawn carefully until it is established and strong.
Best Time To Sow Grass Seed
Although you can scatter seed at any point during the growing season, you will get the best results if you align your seeding with the natural cycle of growth. Different varieties of grass will grow better at different times of the year, so be sure you get the right kind for your climate and planting season.
There are cool season grasses and warm season grasses.
Cool-season grasses grow best during cooler temperatures, usually in the fall and spring. These grasses do well in cooler areas of the United States, such as the northeastern areas. Cool-season grasses include:
- Kentucky bluegrass
- Perennial ryegrass
- Tall fescue
Warm-season grasses will germinate and grow best during the time of year when the temperatures are warmer, such as late spring and into the summer. They also grow well in warm climates, such as the southern areas of the United States. Warm-season grasses include:
- Bahia grass
- Zoysia grass
- Centipede grass
Choosing the right seed for the right time of year will help your lawn get off to a great start so it can grow and thrive.
Cool Season Grass Seed
Fall is the best time to grow cool-season grass seed. This is because the soil is still warm from the summer and the daytime temperatures are moderate, but not too hot. Cool evenings help keep the soil from getting too warm during the day. This balance of temperatures creates the ideal conditions for cool-season grass seed to germinate.
Soil temperatures should be between 50°F and 65°F when you sow your grass seed. You will want to plant any cool-season seed a minimum of 45 days before the first frost for your growing zone so the grass has time to get established before the frost hits. Fall precipitation means you will need to water less and the seed will be less likely to dry out.
Spring is also a good time to plant cool-season grass seed, however, the soil temperatures may not be quite warm enough for grass seed to germinate. You will need to make sure the soil temperature and air temperature are just right for success.
A wet spring can also give weeds a big advantage over young grass. If warm temperatures set in too quickly, it could stress new grass causing deterioration leading to failure.
Warm Season Grass Seed
Warm-season grass seed germinates once the daytime temperatures are around 80°F and the soil temperatures are between 65°F and 70°F. The planting dates for warm-season grass will depend on your growing zone
Avoid planting warm-season grass seed until all risk of frost has passed or your tiny grass seedlings may suffer from freeze burn and die. If the overall soil temperature is too cool or too wet for this type of seed, it will most likely rot.
Warm-season grass needs to be planted at least 90 days before the first frost date in your growing zone. This type of grass will go dormant when temperatures drop down into the fifties, so the seedlings need plenty of time to get established before the cool weather sets in.
Good timing will help the seedlings germinate and thrive before the fall weather hits.
It is possible to overseed warm-season turf with a cool-season grass to add some green for the winter. This should be done in early fall and will extend the seasonal life of your lawn.
Will Grass Seed Germinate On Top Of Soil
There is no need to plant your grass seed under the soil. In fact, grass seedlings are not particularly strong, and may not be able to work their way up through the soil once they germinate. If there is too much soil over the grass seed, it simply won’t be able to grow.
Instead, grass seed should be spread over top of loose, prepared soil or over-sown onto an existing lawn.
How To Speed Up Grass Seed Germination
If you want to speed up grass seed germination, you can help it along with pre germination. To pre germinate grass seed, place the seed in a bucket with a moist compost mix. Allow this mix to sit for about three to four days.
Once the seed begins to swell, they will produce a tiny growth. Spread the seeds out on a dry surface for about twelve hours to allow them to dry a little bit. After the seeds have dried slightly, you can spread them out into your lawn.
Watering New Grass Seed
Grass seed needs regular watering to get established. The amount of sunshine and shade alongside the temperature of the air and soil will have an effect on how quickly the soil dries out, so you will need to keep monitoring it.
Try to keep the top two inches or so moist but never soggy. After the lawn is well established, it will need about an inch of water per week. Morning is the best time to water before the sun is too hot. Watering at night may promote mold or fungus and should be avoided when possible.
New Lawn Care
Once you’ve successfully germinated and grown your new lawn, it’ll need regular care and maintenance. There are a number of basic measures you can take to give yourself the best chance of enjoying a green and vibrant lawn:
- Water correctly. Too little or too much water is the leading cause of new-lawn failure. Be sure to plan ahead so you can water your new lawn appropriately. You’ll need to keep the soil moist when your grass seeds are germinating, but once the seedlings reach 2 inches in height, you can reduce the watering frequency.
- Fertilize at the right time. Don’t fertilize your new lawn for at least the first six weeks of growth. If your soil is in good condition you may not need to apply any at all. If your unsure, wait and apply fall fertilizer. Test your soil.
- Avoid foot traffic. Try not to play on or walk on new lawns for the first three weeks of growth.
- Do not mow too soon. Wait to mow your lawn until it is 3 to 4 inches tall. The first time you mow your new lawn, just cut it slightly to make it look neat but be very careful not to pull out the tender seedlings.
The next time you mow, you can cut the lawn to the maximum height recommended for your type of grass. Never remove more than 30% of its height at a time.
So, How Long Does It Take Grass Seed To Grow
Well, how long does it take grass seed to grow? I know…there is no simple clear cut answer to this. But as we’ve revealed grass will germinate in around 5-22 days depending on the variety, and it will grow about 1-3 cm per week depending on the environmental conditions.
However, there are so many species of grass used in lawn growth and so many man-made factors and influences. So, perhaps it’s worth starting off with our guidelines and working with nature and shepherd your lawn to grow at its own pace.