Lawns are everywhere. Some are highly tended; others, not so much. My own lawn is a mixed planting of three types of turf grass (Kentucky blue, fescue, and perennial rye grass), clover, violets, ground ivy, and various other “weeds”, which is exactly how I like it (and so do the resident honey bees and bumble bees!). Regardless of how perfectionistic you are about your lawn, at one point or another, you’ll find yourself needing to plant grass seed. Whether it’s to fill in a bare spot left behind by Fido or a wayward snowplow, or to install a brand-new lawn after a construction project, learning how to plant grass seed is a necessity for most homeowners. This article offers a simple guide to success, no matter the reason for your reseeding efforts.
Start with the best type of grass for your climate
As a professional horticulturist and a former landscaper, I’ve seeded dozens of brand-new lawns over the years, and I’ve over-seeded bare spots in hundreds more. No matter how large or how small your job is, success always starts with selecting the best grass seed for your region. Different grass species thrive in different climates. There are cool-season grasses and warm-season grasses. The label of the package will tell you which grass varieties are included. It will also tell you whether or not there is a starter fertilizer included. Do not choose a blend that includes weed control products. They could harm young seedlings.
Which grass seed is best for your yard also depends on the amount of sunlight it receives. I suggest contacting a local garden center or feed store and speaking with them about the best options for your region. There are also some useful online maps with all the information you’ll need to choose the appropriate grass species for your growing conditions if you live in the US.
Some brands of grass seed come blended with a “filler” product intended to help you distribute the seed evenly and to act as a protective covering. I personally avoid these products because they are more costly than purchasing a bag of high-quality plain seed and they don’t cover as large of an area.
Preparing the ground for planting
After selecting and purchasing the seed, it’s time to prepare the soil for the planting process. This is a very important step in knowing how to plant grass seed successfully. The tender roots of young grass plants will not grow well in compacted soils so it’s essential that this step be done properly. Here are instructions for prepping the ground to overseed bare spots in an established lawn and instructions on how to prepare for planting grass seed in a large bare area.
Preparation for seeding a bare spot in the lawn: Begin by using a cultivator to remove the dead grass. If it’s a small spot, use a hand cultivator. If it’s a larger spot, use a diamond hoe or warren hoe. Then, dig up the area down to a depth of two or three inches with a shovel or trowel. Loosen the soil and break up any clumps.
Preparation for planting grass seed in a large bare area: If you want to know how to plant grass seed in larger areas successfully, begin by loosening the top three to five inches of soil. Use a rototiller for the job if it’s a very large lawn area. Use a shovel or hoe if it’s an area that’s just a few square feet.
Whether the area is small or large, after loosening the soil, it’s time to rake it smooth. Use a bow rake or a seeding rake to further break up any soil clods and rake the soil out into fine particles and a smooth finish. Use the tines of the rake to smash any large clumps of dirt if necessary.
The final step of site preparation for planting grass seed is to water the area well. Putting seed down on damp soil encourages speedy germination and provides immediate moisture to emerging roots.
How to plant grass seed
For small areas, use your hand to distribute the seed, flinging it out over the area. For large areas, use a walk-behind broadcast spreader or a hand-held hopper spreader to disperse the seed. It’s all too easy to put down too much seed, or conversely, not enough seed. When you’re finished, the grass seeds should be evenly spread over the soil surface. They should be about one-quarter to one-half inch apart (obviously no one expects you to actually measure – just eyeball it). If you sow grass seed too thickly, the plants will outcompete each other and their growth will suffer. If you don’t sow them thickly enough, weeds may move in.
How to ensure good coverage
Sometimes it’s challenging to ensure ample coverage of grass seedlings. If you are using a drop spreader, I suggest distributing the seeds in one direction and then making a second pass in the perpendicular direction. This two-directional overseeding promotes more even grass seed germination and distribution. If you are spreading the seed by hand, it’s a bit easier to eye, but dropping the seeds from different angles helps.
What to put on top of newly planted grass seed
After the seeds are sown, cover them immediately to protect them from birds, keep them moist, and prevent them from washing away in a heavy rain. There are several different mulches you can use for the job. In my experience, straw (not hay, which can be filled with weed seeds), screened compost, or mushroom soil are prime choices. These products also act as soil amendments when they break down and can improve your soil’s fertility and structure. All three of these options are available from your local garden store or landscape supply center. Erosion mats are another option. They can easily be unrolled over the area with little mess and are biodegradable, though they’re also a good bit more expensive than the previous choices. Peat moss is not a good idea because it can repel water once it has dried out.
No matter what you choose to use to cover grass seed, more is definitely not better. One-quarter of an inch is about as thick as you should go. Compost and mushroom soil are great for covering fall-seeded lawns. Their dark color absorbs the sun’s heat and keeps the soil warm all night long. This speeds germination and encourages rapid lawn establishment prior to winter’s arrival.
How long does it take for grass seed to germinate
Some varieties of turfgrass take longer to germinate than others. For example, perennial rye grass germinates in as little as 3 to 5 days, fescues take more like 10 days, Kentucky bluegrass takes 2 to 3 weeks, and warm-season grasses like centipede, Bermuda, and zoysia grasses can take over a month. If your grass seed is a mixture of varieties, know that not all of them will germinate at the same time. To encourage good germination and a healthy start no matter which type of grass seed you planted, it’s critical that you keep the seeded area and the young plants well-watered until they are established. See the section below on watering for more info on how and when to water new grass.
Planting grass seed in fall
In many climates, the best time to plant grass seed is in the autumn. The still-warm soil of late August, September, October, or November encourages optimum root growth, while the cooling air temperatures discourage excessive top growth. This is perfect for establishing lawn grasses and promoting extensive root growth. It also makes the turf more resistant to drought and better able to access nutrients in the soil. In addition, in most regions, fall also brings increased amounts of rainfall. This means you won’t have to lug out the hose and sprinkler as often.
It’s time to plant grass seed in the fall when nighttime temperatures drop down to about 60 degrees F. Keep an eye on the forecast. Opt for sowing grass seed when there’s a day or two of rain predicted.
Planting grass seed in spring
Spring is another great time to seed the lawn. It’s particularly good if you live where springs are long and cool. For spring planting, it’s absolutely essential that you continue to regularly water the seed and the sprouted grass through the remainder of the spring, summer, and well into the fall. Establishment failures are often connected to improper watering. Early summer is another possible time, but you’ll need to water more often.
How often to water grass seed after planting
Water newly planted grass seed daily if the weather is over 80 degrees F. Every other day is a good watering schedule if temperatures are cooler. Prior to germination, wet the top inch or so of soil. But, once the grass seed germinates and begins to grow, reduce the frequency of irrigation but water more thoroughly. Once your new grass is about two inches tall, reduce your watering schedule to once or twice a week, but water until the ground is wet down to a depth of about three inches.
Once grass is fully established, stop irrigation all together, unless there’s a prolonged period of drought. When it comes to watering established lawns, it’s always better to water less frequently but very deeply. Always water lawn in the morning, if possible, to reduce the chance of fungal disease issues.
When is it safe to mow new grass?
Mow new grass when it reaches a height of about 3 inches. Mow high through the first growing season (3 to 4 inches). Make sure your mower blades are sharp (here’s my favorite sharpening tool) so they cut the grass cleanly, rather than tearing it which can create an entryway for disease.
When to fertilize new grass
When learning how to plant grass seed, many people think you should add fertilizer at planting time. This is not a good practice however, because fertilizers (especially salt-based synthetic lawn fertilizers) can burn tender young grass roots. Instead, top-dress the lawn with compost (here’s how) or use an organic granular lawn fertilizer instead of a synthetic brand. You can start to fertilize new lawns after you’ve mowed the grass 6 times.
Now that you know how to plant grass seed, it’s easy to see how doing it right can make all the difference. Follow the steps outlined above and you’ll have a healthy, thriving lawn instead of one that’s struggling.
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