Growing a new lawn from grass seed is one of the easiest — and most-satisfying — home improvement tasks a homeowner can tackle. With just a little time and know-how, you can bring to life a beautiful expanse of green grass.
Here’s how to grow a lawn from grass seed, in six simple steps.
Step 1: Get rid of the old sod
Out with the old. Your new lawn does not want to compete with old sod and weeds.
If you have a small area where you plan to seed grass, hand tools are sufficient to do the job. Get in there with shovels and rakes and dig out the old sod and weeds.
If you plan to remove all vegetation, it may be simpler to use a nonselective broad-spectrum herbicide that will kill any plants it contacts. Follow label instructions carefully and be sure it doesn’t overspray or run off the area where you want it applied.
Whichever method you use, though, don’t overdo it. You want to loosen the soil and get rid of the old vegetation but leave that precious good topsoil behind.
Once you have removed the weeds and old sod, loosen the soil. You don’t need to turn the topsoil over. Just break it up so the new grass seeds’ roots can easily grow through. If you just have a small area to seed, a digging fork will do the trick. For larger areas, consider a core aerator. You can rent one and do the job yourself, or hire a lawn care company to do it for you.
While you have the soil bare is a perfect time to attend to any grading issues your future lawn will have by filling in low spots. Use a half-and-half mixture of sand and topsoil to fill any low spots.
An even lawn without bumps will prevent accidental scalping of your future lawn.
However, not all hills need to be evened out. In rainy parts of the Pacific Northwest, for example, a slight slope is desirable to allow excess rain to flow off.
Get the timing right: When to seed
For cool-season grass seeds, either spring or fall are the preferred times, since these northern varieties of grass prefer warm soil and cool air.
In the South, warm-season grasses can be planted from late spring to mid-summer. Wait until the last chance of a late frost has passed, and the daytime temperature is in the 80s.
Step 2: Test and amend your soil
You have exposed and evened out the planting surface, but it’s not yet time to lay down the seed. For the seeding project to have the best chance of success, you need to know what kind of soil you have. So test.
Good: At a minimum, test for pH. That’s a measure of the acidity or alkalinity of your soil. Most grasses like slightly acidic soil, with a pH of 6.2 to 7.
A simple moisture and pH tester can be found for $10 or less.
Better: Also test for the major nutrients in your soil. For around $20, you can get a kit that in addition to testing for pH, will test for the major plant-building nutrients, nitrogen, phosphorus and potash — the N, P, and K numbers you see on all bags of fertilizers.
Best: Test for both major and minor nutrients. There can be more than a dozen you can test for, and which ones you test for will vary depending on the testing facility and on which micronutrients tend to be lacking in your area. For that, you’ll need either a fancier kit or take your soil samples to a testing lab.
There are private laboratories, and also many state extension service offices. The latter often offer low-cost or even free soil testing.
Test the soil as soon as you can. There can be a wait of up to two weeks to get test results back. If you dawdle, you could miss your ideal planting window.
The test results should give you a plan, and maybe a shopping list for your local garden shop. Following application directions carefully, add your soil amendments to restore what it lacks. Till your soil to a depth of about five inches, working the soil amendments in evenly.
Step 3: Select your grass seed
One of the biggest keys to success is picking a high-quality seed that is right for your climate.
Best grass seeds for Northern states
If you live in a Northern state, select a cool-season grass. Cool-season grasses thrive in the late spring and early fall months in the northern two-thirds of the United States. Northern grass seed products grow best when temperatures are 60-75 degrees Fahrenheit.
The most popular cool-season lawn grasses are:
- Bentgrass seed. One of the standard grasses for golf course putting greens, some bentgrass varieties, such as Colonial Bentgrass, are made for home lawns. It likes to be cropped short.
- Kentucky bluegrass seed. This is the classic choice for Northern lawns and was brought to the United States during the colonial days. Wants full sun, not shade tolerant.
- Fine Fescue seed. This perennial bunchgrass doesn’t mind poorly drained areas.
- Tall fescue mix seed. Puts down deep roots, so a tall fescue lawn is drought tolerant.
- Creeping fescue seed. Although slow to germinate and spread, this fescue seed has tolerance for shade, and low maintenance requirements make it a good choice for large expanses. It is also a good companion for bluegrass since it will thrive in shady spots where bluegrass will not.
- Ryegrass (annual or perennial) seed. The annual variety is used for a quick shot of green. Its permanent, perennial cousin is noted for its wear tolerance, so it’s a good choice for places where children will romp.
Best grass seeds for Southern states
People living in Southern states should select a warm-season grass seed. But the variety of seed will depend on what part of the country you are in.
In the warm, humid Southeast and Gulf Coast states, the favorite seed varieties are:
- Bahiagrass seed. Coarser than any Northern grass, but it grows thick and dense and is tolerant of both heat and drought.
- Bermuda grass seed. This is a hardy but needy grass, which requires high maintenance but stands up well to heavy traffic.
- Buffalograss seed. This warm-season grass seed is the only variety native to North America, so it doesn’t need much help to thrive. It is highly drought tolerant and needs little care.
- Centipede grass seed. This grass is slow to grow, but very low in maintenance once established. In climates that stay warm, it has virtually no dormant season, so it stays green year-round unless there’s a cold snap.
- Zoysia grass seed. A slow grower, but one of the most cold-tolerant varieties of warm-season grasses.
Another common turfgrass choice in the Deep South, St. Augustine grass, is not commercially sold as seed, since its seedheads are sterile. It is a grass planted from sod.
Transition state grass seeds
In between the North and South is the transition zone, where there are both hot summers and freezing winters. Finding a variety of grass seed that works will be a tradeoff: You either find the most cold-tolerant warm-season grass available, or the most heat-tolerant cool-season grass.
Single variety, blend or grass seed mix?
In addition to getting a high-quality grass seed that matches your climate, you also need to consider your lawn’s unique properties. Look over the area where you intend to seed.
- Is it in full sun or shady, or a mix? You can get a shade mix of seeds if your lawn has dense shade.
- How much moisture will it get?
- Is the area heavily trafficked?
- How much time and effort do you want to spend on maintaining the lawn?
Knowing your terrain will help you home in on the formulation of lawn seed you want. Seeds are sold as pure seed of one variety, blends (multiple types of the same variety) and mixtures (seed blends of different varieties).
Each type of grass seed has its uses. The pure seed will give you a unified look. The blends will be a bit less uniform, but one variety may cover up for the weaknesses of another. Grass seed mixtures provide the most biologically diverse lawn: The grass plants won’t look identical, but the diversity gives you the greatest chance of having your lawn survive diseases and droughts. Pennington, for example, has a Smart Seed brand that includes a mix of shade grass seed and full-sun seed.
Federal Seed Act guarantees accurate labeling
When it comes to selecting seeds, you have an ally — the Federal Seed Act. First enacted in 1939 and amended five times since, the Seed Act requires seed sellers to provide consumers with valuable information on the seed’s labels.
Under the law, the label must tell you:
- The name of the grass variety (or varieties).
- Its purity, that is, the weight by percentage of each type of seed.
- Germination percentage. The percentage of the seeds that you can expect to germinate. This is not a number the seed companies can fudge. The federal government expects seed producers to run regular germination tests and keep careful records.
- Weed seed percentage. Look for a seed that has less than 0.5 percent weeds.
Grass seed alone? Or a fertilizer and mulch mix?
You have one final decision to make — whether to buy a seed product that incorporates fertilizer and mulch, or whether you will purchase fertilizer and mulch separately.
The all-in-one products tend to be more expensive, but are more convenient.
Measure your lawn area in square feet, and purchase enough seed to cover that area. Generally, the bags are marked as the number of pounds needed per 1,000 square feet. Fudge your purchase on the high side so you’ll buy a little more than needed. That way you should have some left over in case you need to come back and reseed some bare spots.
If you are fertilizing separately, broadcast the fertilizer per the manufacturer’s instructions, but do not till it in.
Step 4: Plant and fertilize your grass seed
With your soil ready, it’s time to lay down the seeds.
For planting grass seed in small areas, hand-seeding is fine. For larger areas, you’ll want to use a seeder. They can be hand cranked, chest mounted or push-from-behind models. Another option is a drop seeder, which drops seeds directly below. They are a good choice for small areas and are more precise than the rotary models. There are more expensive commercial seeding options as well.
Follow the instructions on the seed bag, but you generally want 15-20 seeds per square inch. Make a couple of test runs, aiming for half of that number since you are going to make two passes with your seeder. If the seeder’s lowest setting is too generous with the seed, thin it out with sand or vermiculite.
Once you get the distribution setting right, make two passes across your lawn area. If you go north-south on the first pass, go east-west on the second. Broadcasting the seed from two angles gives seed the best chance to spread evenly.
“We call it ‘the seed-soil contact,’” said University of Illinois Extension office educator Richard Hentschel. “You want good seed-soil contact. If the seed and soil are not in intimate contact, the little root radicle may die out before it hits the soil.” The radicle is the first root to emerge from a seed.
Rake the seeded surface lightly to mix the grass seed and fertilizer in the top 1/8-inch of soil. If you have access to one, roll using an empty roller to improve the germination rate.
If you have a hilly area, seeds will tend to wash away to a low point. One potential solution is hydroseeding: broadcasting seeds that are suspended in a fertilizer-mulch slurry. Professional landscapers often offer hydroseeding services, and there are some hose-end sprayers for the do-it-yourselfers.
Lawn-starting fertilizer: Watch the phosphorus
A word about using lawn-starting fertilizer: Be mindful how you do it, particularly with one element — phosphorus. In the three big letters on a bag of lawn fertilizer, phosphorus is the middle number. Traditionally, fertilizers made for new lawns contained a good strong dose of it because phosphorus encourages root growth.
Not anymore. The use of phosphorus has become controversial and for good reason. While the element is essential for the root system to grow, its overuse has led to over-blooming algae and dead zones in bays, rivers, and lakes.
Alarmed by the evidence that excess phosphorus runoff was causing damage, lawn fertilizer makers began formulating phosphorus-free alternative products. One of the giants in the industry, The Scotts Miracle-Gro Co., removed phosphorus from its popular Scotts Turf Builder fertilizer in 2013 out of concern for the environment.
Arguing that sufficient phosphorus is available in soils already, 15 states have restricted the use of fertilizers containing the nutrient. They are:
- New Hampshire.
- New Jersey.
- New York.
Washington, D.C., also restricts phosphorus use.
Most of the laws carve out an exception and allow limited application of phosphorus on new lawns, but turf experts say let your soil test be your guide. If it says that your soil lacks phosphorus, then it’s acceptable.
Do take care when applying phosphorus or any fertilizer. Apply only the nutrients your soil test says you need and follow directions carefully. Clean up any spilled fertilizer and don’t water so much you create runoff.
Step 5: Water and watch: Your post-planting chores
All your hard work so far will go for naught unless you keep an eye on the fledgling grass seeds and attend to their needs as they emerge. Seeds only get one shot at germination, so what you do now is critical.
That means water.
You want to keep that top layer of soil ¼ to ½ inch deep moist. If a grass seed dries out, it dies out. Some have likened this part of lawn-building to caring for an infant because both young babies and young lawns need constant attention.
Likely you’ll be dealing with several variables. Part of the lawn may be shadier, part may have more porous soil, or part may be sloped. So observe and adjust your watering accordingly.
Keep the soil moist, but too much water is as bad as too little. Overly vigorous watering could wash the seeds away. So keep the soil moist but not soggy. A misting attachment on your hose can cut down on the amount of force you use.
Expect to water at least once a day in the morning, and perhaps again in the afternoon if sun and wind have dried out the soil.
Keep in mind that different grass plants germinate at different times. So if you have a mixture of grass seeds, you’ll need to keep watering it until the slowest-germinating species emerges.
Grass seed germination rates, by grass type
- Bahiagrass seed: 10-28 days
- Bermudagrass seed: 7-28 days
- Kentucky Bluegrass seed: 14-21 days.
- Buffalograss seed: 7-10 days.
- Centipede grass seed: 14-28 weeks.
- Fescue grass seed: 10-14 days.
- Annual ryegrass seed, perennial ryegrass seed: 5-10 days.
- St. Augustinegrass: Rarely grown from seed, propagated by plugs and sod.
- Zoysia grass seed: 14-21 days.
Even if you planted just one turfgrass variety, the grass seeds won’t all pop up at once. Some will be buried a bit deeper or have a different rate of water absorption. Stay with your watering regimen until you are sure you have given all the seeds the best shot you can at taking root.
Keep foot traffic to a minimum during this time. You can also consider putting up “Please keep off the new grass” signs to discourage accidental trampling by your kids and neighbors (and their dogs).
Step 6: When to give new grass its first mow
Hooray! It’s green and it’s growing well.
Here’s how tall your grass should be before you mow for the first time:
- Bahiagrass: 2-2 ½ inches.
- Bentgrass: 1 inch.
- Bermuda: 1½-2 inches.
- Bluegrass: 2-2½ inches.
- Buffalograss: 2-3 inches
- Centipede: 1½-2 inches.
- Fescue: 2-3 inches.
- Perennial Ryegrass: 2-3 inches.
- Zoysia: 1-2 inches.
Mowing a new lawn: Be gentle
Be careful with the lawnmower the first few times your new turfgrass is mowed. The roots will not be long or well-established, so it will be easy to accidentally rip up the young plants. Sharpen the mower’s blade, so you cut, not tear the tender plants. Try to start the mower on a flat surface away from the lawn, and minimize the number of turns you make with the mower. Abide by the rule of ⅓, which is to never remove more than a third of a grass plant in one mow.
Once you have mowed at least once, cut back on your frequent shallow watering, and switch to watering a couple of times a week, deeply. Get water down to six or eight inches deep to encourage your new lawn to root deeply. Once established the lawn will start spreading to cover any gaps.
After about six to eight weeks, your lawn should be well-established. Hit it with a little more fertilizer to encourage deep roots, and take down your “keep off the new lawn” signs. Your new lawn is ready for you.