It can be tempting to simply spread some grass seed in your yard and be done with it, but this is not the ideal way to seed your lawn. Yes, some of the grass seed will grow without any other steps. However, you’ll likely end up throwing money down the drain when most of that grass seed doesn’t germinate and is food for the birds. In this article I’ll answer the question “Will grass seed grow if not covered?” and explain the best way to successfully grow a lawn from seed.
This article was last updated on by Lawn Chick Owner Sarah Jameson
Article content reviewed for accuracy by Certified Horticulturist Nicole Forsyth, M.S.
If you are reseeding bare patches of your yard, then adding some mulch to cover your grass seed will be important. Without protection from existing grass, seed will be vulnerable to the elements.
If you do have some existing grass, then the seeds might be slightly more protected as long as the lawn is not too sparse or dry.
So, Will Grass Seed Grow if Not Covered?
Grass seed can grow if not covered, but it is usually beneficial to add a layer of compost, topsoil or straw mulch over the top of your seed to keep it moist and help with germination.
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Here’s What Experts Recommend
According to Zac Reicher and Keenan Amundsen, professors in the Department of Agronomy and Horticulture at the University of Nebraska-Lincoln, “seed should be applied using a drop spreader because rotary spreaders do not disperse the seed uniformly.”
They add that “spreaders typically do have calibration information on seeding turfgrasses,” and for many homeowners “the easiest way to apply seed uniformly to a small area is to calculate and weigh out the amount of seed needed for the area.”
Personally, I prefer a broadcast spreader for the job, but I agree about seeding according to grass type, square footage, and weight.
Please use my free lawn size measuring tool and grass-seed calculator to set yourself up for a successful project.
Why Seed Should Not Be Exposed to the Elements
There are a few reasons why you shouldn’t just sprinkle grass seed on your lawn and leave it exposed to the elements.
Germination is the process of a seed sprouting and it can take a few days, to a few weeks to occur. In order for any type of seed to germinate, it needs certain things. Not only do you need your soil to be the right temperature for germination, the most critical component of germination is appropriate moisture.
To sprout, the seed needs to be moist and warm. Without enough water, grass seed is unlikely to sprout, and without some sort of mulch or top-dressing, most seed will dry out.
Expert Explains Rationale for Covering Your Seed
When it comes to mulching your seed, horticulture professor Zac Reicher from the University of Nebraska-Lincoln explains that “Mulching the area will prevent erosion and conserve water. Therefore, mulching is most important when it is impossible to adequately irrigate newly-seeded areas.”
He says that “One bale of clean (weed-free) straw/1000 sq ft will give you a light covering that will not have to be removed after germination.” He warns against using “too much mulch, which will shade seedlings and have to be raked off later.”
So, you should “apply the mulch lightly so you can still see approximately 50% of the soil through the mulch layer.” Zac points out that “mulching is most important in dormant- or spring-seedings, or unirrigated late-summer seedings.”
Root Development
The seeds that do germinate can still struggle to get properly rooted, which will make your grass seedlings susceptible to damage.
Roots that are too shallow in the ground also prevents the grass from being able to reach moisture and nutrients below the surface, and your mower will actually rip your seedlings up rather than cutting the blades.
Grass Seed vs. Bird Food
Leaving seeds exposed can also make them an easy food source for birds. Covering them up hides them from wildlife and gives them a better chance of not being eaten.
It is incredibly frustrating to spend good money on grass seed only for it to become someone’s dinner.
Bird food is a lot cheaper than grass seed.
Prevent Runoff
A heavy rainfall can wash your grass seed away.
Remember, the germination time of grass seed may take anywhere from 5 to 21 days depending on the species. In that time it does not have roots to hold it in place if it should rain. It typically takes 4 to 10 weeks for new grass to root well and become established.
Without covering your grass seed, the seed is easily swept up and carried to a sewer grate or to low points on your property where you didn’t need extra grass seed.
Preparing the Soil
The best new lawns start with proper preparation.
Testing the pH of the soil will help you determine if you need to add anything to have it at the ideal pH, which would be between 6.2 and 7.0. Inexpensive pH test kits are available at most local hardware stores. You can amend your yard with lime to improve your pH if needed.
I use and recommend this soil test kit from Amazon which gets you a full soil lab analysis. Knowing what your lawn needs (and doesn’t) can improve your results and save you a lot of money on fertilizer and products many lawns don’t actually need. It’s well worth the money if you’re serious about lawn care – I use this kit once every year on my property.
Almost every yard will benefit from aeration prior to seeding.
Yards with heavy clay soil, or which have a lot of foot traffic will benefit from aeration. By aerating your turf you will allow it to loosen up, get better seed to soil contact, and improve water penetration and airflow (which improves root development).
Loose soil and the pockets created by aeration give the grass seed somewhere to go that is beneath the soil and also allows for better root development. For small jobs don’t rent a core aerator, just take an iron rake and loosen the top layer of soil enough to provide some good contact points for your grass seed.
Mulch Options to Cover Grass Seed
There are quite a few options when it comes to covering your newly laid grass seed in order to protect it and keep it moist.
Each has their own advantages and disadvantages, and what works best for you may not be best for someone else.
Keep in mind that even a quarter of an inch of compost or soil can provide adequate protection.
Compost or Top Soil
One of the simplest ways to cover up grass seed is by spreading a layer of screened compost or topsoil.
Either product is available at garden centers for small jobs or, for a larger yard, your local nursery or box store can arrange a bulk delivery for you.
Compost is my favorite top-dressing material for new lawns because it retains moisture well, improves your soil, and acts as a natural fertilizer for your seedlings.
These products are easy to spread over the grass seed. You can invest in a rolling compost spreader like this one on Amazon, or do what I do and use a large snow shovel and take a big scoop and then broadcast it by hand by flicking it off the shovel, then spread it gently with the back of a leaf rake.
You can spread topsoil or compost with some seed spreaders or lawn rolling drums like the one I just linked.
I recommend that you prepare the site by loosening the soil, spread your starter fertilizer and seed, then top-dress and water well.
Straw Mulch
A very thin layer of straw over your lawn is a popular, and inexpensive way to protect your grass seed.
Before spreading your seeds, it is still important to rake the soil to loosen the top layer and prepare your site, and after broadcasting your starter fertilizer and seed, work the seed in with the back of a leaf rake.
Next, add a layer of straw that is just barely there. You want it loose and not too thick so that air can circulate and light can reach the seedlings.
Try to get straw that does not have seeds, or you’ll have some weed removal to do if you plan to mow it in. Gently rake it up after you establish your grass if you would prefer.
Certified horticulturist Nicole Forsyth recommends that you try “Salt Marsh Hay, which is naturally seedless for this type of mulching” if you’re concerned about straw seeds germinating in your lawn.
Bagged Grass Seed Mulch
Specially formulated mulch is another popular option to use while reseeding a lawn. Some companies develop varieties specifically to be used with grass seed. These will be biodegradable. It will also be light enough not to smother the grass seedlings. Never use a traditional bark mulch product over grass seed.
A proper grass mulch product breaks down over time and blends in with your lawn.
The advantage of using this method over straw is that it does not need to be raked up afterwards.
Nicole Forsyth, a certified horticulturist and member of our expert panel, recommends using leaf mold instead. “It’s high in organic matter, easily accessible, non-smother of the seed, and stays moist,” she says.
Lawn Clippings
Grass clippings can be an excellent alternative to straw or mulch that combines the best of both worlds, but you have to be careful to spread them evenly and not too thick.
Bag your grass clippings prior to spreading seed, and let them dry. Then spread them lightly on the lawn along with your grass seed. Over time, the clippings will break down and become part of the soil. You won’t smother your seedlings if you keep it light and thin.
Tamping in Your Seed
A lawn roller like this one on Amazon can be another helpful tool to tamp the seeds into the soil. I find that this creates great contact between seed and soil. It can work well whether you tamp them into your own well-raked or aerated soil or a layer of fresh topsoil you’ve spread in your yard.
Increasing the contact between the seed and the soil will ensure that your seed stays moist longer.
If you’re on a budget, a wooden board or a doormat can also have the same effect. Put one end of the board or mat on the ground, lift up the other end and drag it across the area you are seeding. It’s less effective and efficient, but it can work just as well.
Getting Grass Seed to Grow if Not Covered
It is difficult for grass seed to grow if not covered. Grass seed is high maintenance, and I’m all for increasing my chances of success and decreasing the number of times I have to water grass seed for good results.
Using some form of mulch after laying grass seed will help ensure that your seed has a chance to germinate. It also protects the grass seed from birds and can help prevent run-off.
It is not expensive or labor-intensive to spread mulch and can save a lot of hassle.
In the long run, while grass seed can grow if not covered, using mulch to keep your grass seed moist will save you money and improve your results.
Still Don’t Want to Mulch?
If you choose to simply spread some grass seed without covering it, picking an all-in-one brand can help.
These all-in-one type products include mulch and fertilizer along with the seed. Scotts and Pennington both sell coated seed products designed to keep the seed moist longer.
Keep in mind that with this type of product, you’ll spend more money because over half the bag you buy probably isn’t grass seed. Check the label to see if it indicates the percentage of weight of your product that is seed versus the percentage of weight that is mulch or fertilizer.
This can give you a better idea of how much bang you are getting for your buck.
Additional Resources
- Care and Maintenance of a Lawn after Seeding by Debra Ricigliano, University of Maryland Extension (link)
- Establishing Lawns From Seed by Zac Reicher and Keenan Amundsen, Department of Agronomy and Horticulture, University of Nebraska-Lincoln (link)
- Lawn Establishment by Peter Landschoot, Ph.D. – Professor of Turfgrass Science, Penn State University Extension (link)