Last Updated on October 30, 2020

How Long for Grass Seed to Germinate?

The winter snow has melted, and the warm winds of spring are finally here. As you look at the results of the ravages of winter, you see bare spots in your grass that were not there before. So you race to the nearest lawn care store to buy grass seed, throw it on the bare ground, hoping it will sprout before it dies out. 

How long does grass seed take to germinate, and when should you call it quits and plant more seed? What makes the grass grow? Keep reading to find out how to get the most from your grass seed and grow a lush, beautiful lawn.

Average Germination Time

Grass seed, when properly planted, takes between 5 to 30 days to germinate, sometimes longer, depending on various factors. Seed variety, temperature, the age of the seeds, and how much or how little water it gets all contribute to how fast or slow it grows. 

Soil health, including a good ratio of nitrogen, also determines how long it takes grass seed to germinate. The best ratio to grow grass seed is three parts nitrogen to one part phosphorus to two parts potassium. A good fertilizer will provide this ratio, of which you can then mix in with the topsoil when planting grass seed.

Seed Variety can Affect Growth Speeds

Grass seed varieties all have different conditions in which they grow best and have different germination times. Depending on the type of seed you planted, you may see grass in a matter of days, or as long as a month.

While Bermuda grass takes between 10 to 30 days to sprout, Ryegrass comes up the quickest, in about 5-10 days. Kentucky Bluegrass takes up to a month to germinate, but rough bluegrass sprouts in about a week.

However, if your seed is a mix of several seed varieties, you may see sprouts in a few days, but will still have grass seed sprouting a few weeks later, as not all seeds grow at the same time. 

What Depth Does Seed Grow Best?

Will grass seed grow if I just throw it down? Or should I cover it? While you don’t want to go very deep with your seed, as it won’t germinate properly, you also don’t want to throw it on the ground without first preparing the soil. The main reason for this is that a good rain could wash the seed away before it has a chance to sprout.

The best depth for planting is ⅛ of an inch to ¼ of an inch.

What Temperature Does Grass Grow? 

First, be sure the soil is warm enough to germinate your seed. It should be 55 degrees, or higher, with the air temperature 65 degrees, minimum. If it is cooler, the seed will not sprout very quickly.

Second, dig up the top layer of soil to get the nutrients from the earth to the top, so your seed has something to feed on and get healthy. 

Third, spread seed loosely in your prepared soil, so they have room to grow. You also want to put the topsoil down loosely, so water can reach your seed while getting air and nitrogen. 

How Much Water is Needed?

Now that you planted your seeds, how much water should you give it, and how frequently? There is a delicate balance between giving grass seed too much water and not enough. Too much water will stop the seed from sprouting, which deprives it of much-needed oxygen. But too little water and your seeds dry out, which also prevents the sprouting process. 

Once your lawn is seeded, aim for watering it every other day. A lawn sprinkler system works perfectly for this, as you can set it for 30 minutes per watering session. But if you have no sprinkling system, aim to get the water at least ½ an inch down into the soil every time you water, to encourage deep roots. 

Be sure to use a fine mist or spray in an indirect manner to avoid rinsing the seed out of the soil.

After your seeds sprout and grow to about 3 inches, you can decrease the frequency of watering to about two times per week.

Does Grass Grow in Winter?

While grass typically does not grow in winter in the northern climates, you can still plant certain varieties of grass seed over the snow. Once the spring thaws come, the seed is carried down into the ground from the melting snow. Whether it germinates or not depends on if it makes contact with the ground. 

HGTV recommends waiting until you see the bare ground before putting down grass seed so it has a chance to bury itself before another round of snow comes back. Once the snow covers the seed again, it has a chance to dig itself into the soil. The Kansas State University Extension office recommends that if you are going to plant grass seed in the winter, wait until at least February. 

If you want to reseed your lawn completely, they say the best time to do that is in September so that the seed can dig itself into the soil with the freezing and thawing of the ground.

Add Organic Material to Give Additional Nutrients to Seeds

Grass seeds are like other seeds in that they need extra nutrition to germinate. When you’re tilling the soil to prepare it for planting, add peat moss, grass clippings, or manure (or a mixture of all three) to the soil. Doing this gives grass seeds plenty of nutrition, as well as aerate the ground so that the seeds can germinate in the best possible conditions. 

As a bonus, adding organic material to the soil keeps it from clumping or becoming hard, which would stop your seeds from germinating. Loose soil is best for grass seeds to sprout.

Conclusion

The last thing to remember is that the more sun the seeds get, the faster they will sprout.

Grass seed can be temperamental at times, but if you spend a little extra time attending to the soil health, watering, and pay attention to the soil temperature before planting, you will see great results in a matter of days.


Author: Matt Hagens

Matt Hagens

Hi, I’m Matt the owner of Obsessed Lawn. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Learn more about me and find me on Facebook.