Overseeding your lawn will thicken the grass, helping it resist future weed invasion. However, it is best used on a lawn where the weeds are currently dormant With just a little know-how, you can bring to life a beautiful expanse of inviting green grass. We break down how to grow a lawn from grass seed into six simple steps How to grow lawn that is lush and full of grass. Checklist to grow a weed-free lawn. Growing a lawn without weeds is a dream for many homeowners. This checklist will help you keep the weeds away from your lawn while maintaining healthy grass and teach you how to make St Augustine grass thicker.
Will Overseeding Choke Out Weeds?
Overseeding your lawn will thicken the grass, helping it resist future weed invasion. However, it is best used on a lawn where the weeds are currently dormant or have recently been killed. Spreading grass seed on a weedy lawn won’t do much good. Weeds that are actively growing in your grass will steal water and nutrients from grass seedlings, causing them to struggle and die. For best results, attack lawn weeds with a weed killer, then overseed to create a healthy lawn that prevents weeds from returning.
Table of Contents
How Does Overseeding Help Prevent Weeds?
Overseeding your existing lawn with new grass seed fills in bare spots and contributes to thicker grass throughout the lawn. A thick grass lawn without bare spots shades the soil below, depriving weed seedlings of sunlight, killing them. Not only that, but thick growing grass pulls moisture and nutrients from the soil first, before weed seedlings can get to them.
- Overseeding contributes to a thicker lawn.
- Bare spots that have been overseeded with grass are less prone to weed invasion.
- Lawns thickened by overseeding prevent weed seedlings from receiving sunlight and nutrients, smothering them.
- Regular overseeding maintains a thick, weed-resistant lawn without herbicides.
Grass plants, like all plants, weaken and die naturally over time. By overseeding you replenish your lawn with new grass plants. This constant replenishment keeps your entire lawn thick enough that it continues to smother new weeds. This reduces the need to use chemical weed killers on your lawn.
Do You Need to Remove Weeds Before Overseeding?
Overseeding is most effective when you kill existing weeds before you overseed. This is because grass can’t choke out existing, established weeds no matter how thick it is. A lush lawn can only stop new weed seeds from sprouting. Also, any weeds that are present when you overseed will steal water, nutrients, and sunshine from your new grass seedlings. Wipe out the weeds to give your grass a fighting chance.
- Remove existing weeds before you overseed.
- Existing weeds won’t be killed or choked out by overseeding. A thick, overseeded lawn will only suppress new weed growth.
- Kill established weeds or they will rob water and nutrients from your grass seedlings.
You’ll get more new grass sprouts from overseeding if you kill existing weeds first. Overseeding a lawn overgrown with weeds will get a poor yield. Your new grass will struggle to compete with the weeds. Paving the way for new grass by killing weeds is your best bet.
What is the Best Time of Year to Overseed a Weedy Lawn?
For the best results overseeding your lawn, you need to seed at the optimal time for your grass type. Warm-season grass lawns (such as Bermuda, Zoysia, and Centipede grass) should be overseeded in spring. Cool-season grasses (Kentucky Bluegrass, Fescue, Ryegrass) sprout and survive best when overseeded in fall.
- Overseed warm-season grasses in spring.
- Overseed cool-season grasses in fall.
- It’s best to overseed when no weeds are present.
Another factor that makes overseeding in fall a great option for cool-season grass lawns is that few weeds will be present. Even if your lawn was infested with crabgrass in spring, by fall it will have begun to drop its seeds and die off. If you overseed in fall, your new grass will sprout and establish itself. By spring, the grass will be thick enough to prevent many of those crabgrass seeds from sprouting.
What is the Best Grass Seed to Use for Overseeding?
The best grass seed for overseeding is grass that will grow well in your climate. In regions with freezing winters, choose cool-season grass. In regions where winters seldom freeze, warm-season grass will perform best.
- Seed with cool-season grass in regions with freezing winters.
- In regions with mild winters, overseed with warm-season grass.
- Match your grass seed to the variety of grass present in your lawn.
It’s also important to note that overseeding is the act of spreading additional grass seed over an existing lawn. It’s usually best to overseed your lawn with the same species of grass that is present there. This will create a uniform, beautiful lawn.
What Grass Will Choke Out Weeds?
The best grasses for choking out weeds in your lawn depend on your location. If you are planting warm season grass and wish to have a weed-resistant lawn, Bermuda grass is your best choice. It spreads through runners and roots to take over areas, which prevents weeds from getting a toehold.
- Bermuda grass is the best warm-season grass for choking out weeds.
- Kentucky Bluegrass is the top option for battling weeds in cool-season grass lawns.
Kentucky Bluegrass spreads faster than any other cool-season grass. It produces roots that form new plants in both spring and fall, meaning it self-thickens and fills in bare spots. If you want to weedproof your northern lawn, go with KBG.
Will Overseeding Your Lawn Get Rid of Weeds?
Overseeding a weedy lawn will not kill weeds on its own. However, thick grass growth produced by overseeding prevents new weeds from sprouting. In order to keep your lawn weed-free with overseeding, first, kill any existing weeds, then prep your lawn and spread new grass seed. The thick growth of new grass will choke out new weed seedlings as they attempt to sprout.
How to Plant Grass Seed in Six Steps
If your spouse keeps telling you the grass is greener on the other side of the fence, you might want to tackle the naked-earth lawn chore you’ve been dodging. We’ll show you how to plant grass seed in six steps. You’ll complete one of the most satisfying outdoor tasks a homeowner can accomplish (and maybe save your relationship).
Here’s how to plant grass seed in six simple steps:
Step 1: Remove the Existing Grass
Is your lawn happily surviving? If your grass is good, but could be better, you could overseed to plump up the existing lawn. For bare spots, use garden tools to roughen up the soil first. Then spread the grass seed over to fill in the bare patches.
If your yard is where feisty weeds go to party and half of your lawn lies naked, you should plan to renovate — remove the old vegetation. New baby grass seedlings cannot compete with that mess. If you’re starting from scratch with a new home build, and establishing a new lawn, you can skip to Step 2.
There are two ways to clean your lawn’s slate:
- Use a nonselective broad-spectrum herbicide. Follow label instructions carefully and don’t spray on a windy day.
- Use a sod-cutter, available at most rental companies. Mark your sprinkler heads before operating the cutter to avoid accidents.
Once the weeds and old sod are removed, loosen the soil bed so the new grass seeds’ roots can easily grow through. You can use hand tools (and your toughest friends), a tiller, or core aerator. You can find tillers and aerators at rental companies, as well.
Fill low spots in your yard using a half-and-half mixture of sand and topsoil. If necessary, grade your yard to keep rain or water flowing away from your home.
Step 2: Do a Soil Test, then Add Amendments
Once you have renovated your lawn – exposed and leveled the planting surface – you’ll need to test your soil for the best grass germination and growth. Test the soil as soon as you can. There can be a wait of up to two weeks for results and you could miss your ideal planting window.
At a minimum, you should test for pH. This is a measurement 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. For about $20, you could test for the major nutrients in your soil. Your results will show the N, P, and K: nitrogen, phosphorus, and potash.
The best soil tests include major and minor nutrients. Your state Extension service and private labs offer these services. Keep in mind your local Extension office can also provide great information and insight that private labs can’t, and usually at a lower cost.
Here are four very good soil tests you can buy on Amazon.
The test results should give you a plan and shopping list for your local garden shop. Follow application instructions carefully and add soil amendments to restore what it lacks. Again, use a tiller or hand tools to work the amendments in to a depth of 1-4 inches.
Step 3: Choose the Best Seed for Your Region
Your local seed expert will always give you the best advice when choosing your seed. Local Extension offices, seed stores, and agricultural suppliers are experienced and understand the microclimates of your area.
In northern states, select cool-season grass, which grows best when temperatures are 60-75 degrees Fahrenheit. Cool-season grasses thrive in the late spring and early fall months in the northern two-thirds of the United States.
People living in Southern states should select a warm-season grass seed. Warm-season grasses thrive from late spring through summer.
Between the North and South is the transition zone where summers are hot and winters are cold. You’ll either need to find the most cold-tolerant warm-season grass available, or the most heat-tolerant cool-season grass.
Best Cool-Season Grasses for Northern States
- Bentgrass is a standard grass for golf course putting greens. Colonial Bentgrass is for home lawns and likes a low mow.
- Kentucky bluegrass is a classic choice for Northern lawns. It likes full sun and isn’t shade tolerant.
- Fine Fescue is a perennial bunchgrass and stands up in poorly drained areas.
- Tall fescue mix puts down deep roots and is drought tolerant.
- Creeping fescue is slow to germinate and spread, but tolerates shade, and is good for large lawns.
- Ryegrass (annual) can be used for a quick shot of green. The perennial ryegrass variety is best for high traffic and playgrounds.
Best Warm-Season Grasses for Southern States
- Bahiagrass has a coarse texture, is heat/drought tolerant, and is best for low traffic lawns.
- Bermudagrass is hardy and stands up to heavy traffic, but it’s high maintenance.
- Buffalograss is the only variety native to North America, highly drought tolerant, and needs little care.
- Centipedegrass grows slowly but has very low maintenance once established. In warm climates, it’s non-dormant, so it stays green year-round unless there’s a cold snap.
- Zoysiagrass is a slow grower, but one of the most cold-tolerant varieties of warm-season grasses.
- St. Augustinegrass is sold as sod, as its seedheads are sterile.
Best Grasses for Transition Zone States
The transition zone is a blend of temperature highs and lows, humidity, summer deluges, and drought.
- Kentucky bluegrass
- Perennial ryegrass
- Tall fescue
Single Variety, Blend, or Grass Seed Mix?
In addition to high-quality grass seed to match your climate, you also need to consider your lawn’s unique properties.
- Is it in full sun, shade, or a mix? A shade mix is great for dense shade.
- How much moisture will it get?
- Is the area heavily trafficked?
- How much time and effort do you want to spend maintaining the lawn?
Knowing your terrain will help you home in on the formulation of seed you want. Seeds are sold as pure seeds of one variety, blends (multiple types of the same variety), and mixtures (seed blends of different varieties).
Pure seed will give you a unified look. Blends will be 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 your lawn has a better chance of surviving diseases and droughts.
Step 4: Best Time to Plant Grass 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.
One of the biggest keys to success is picking a high-quality seed that is right for your climate.
Federal Seed Act Ensures Proper Labeling
When it comes to selecting seeds, the Federal Seed Act requires seed sellers to provide consumers with valuable information on the seed’s label.
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.
Pure Grass Seed or Fertilizer/Mulch Mix?
You have one final decision to make. Are you going to purchase a seed that incorporates fertilizer and mulch, or purchase fertilizer and mulch separately? The all-in-one products are more expensive but are convenient.
Measure your lawn area in square feet, and purchase enough seed to cover that area. Usually, seed bags are marked as the number of pounds needed per 1,000 square feet. If possible, buy a little more than needed in case you want to reseed some bare spots.
If you are fertilizing separately, broadcast the fertilizer according to the manufacturer’s instructions.
Plant your Grass Seed and Fertilizer
To plant grass seed in small areas, hand-seeding is fine. For larger areas, seeders and spreaders provide more precise coverage. You can find hand-cranked spreaders, chest-mounted, or push-from-behind seeders. Drop seeders drop seeds directly below the unit. There are more expensive commercial seeding options as well.
Follow the instructions on the seed bag. If the seeder’s lowest setting seems too generous with the seed, thin it out with sand or vermiculite.
- For large lawns, fill the push spreader with seed.
- Spread half of the recommended seed north to south.
- On the second pass, spread east and west for even coverage.
- Rake the top ⅛-inch of the seeded surface lightly. Using the back of a leaf rake side-to-side makes this an easy job.
- If you have access to one, roll an empty lawn roller to improve germination.
“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.
If you have hilly areas, 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
You need to find out if your state restricts using fertilizers containing phosphorus. Most laws carve out an exception and allow limited application of phosphorus on new lawns, but turf experts say to let your soil test be your guide. If it says that your soil lacks phosphorus, then it’s acceptable.
Step 5: Aqua and Attention
Keep a careful eye on your new grass seeds. They only get one shot to germinate, so what you do now is critical. That means water. 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 them until the slowest-germinating species emerges.
- Keep the top layer of soil moist (but not soggy) down to 1/2 inch. (Too much water is as bad as too little, and overly vigorous watering could wash the seeds away.)
- Water at least once a day in the morning and perhaps again in the afternoon if the sun and wind have dried out the soil.
A misting attachment on your hose can cut down on the amount of force you use. Part of your lawn may be shadier, part may have more porous soil, or part may be sloped. Adjust your watering according to your lawn’s needs.
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’re sure the seeds have germinated.
Keep foot traffic to a minimum. You could 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 your New Lawn its First Mow
Hooray! Your new lawn is 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 inche
- Centipede: 1½-2 inches
- Fescue: 2-3 inches
- Perennial Ryegrass: 2-3 inches.
- Zoysia: 1-2 inches
Treat your New Grass like a Baby
Take advice from the ‘70s band, The Eagles. Slow down and take it easy the first few times you mow your new turfgrass. The roots won’t be long or well-established, so it will be easy to accidentally rip up the young plants.
Here are a few tips to ensure a successful first mow:
- Sharpen the mower’s blade so you cut, not tear, the tender plants.
- Start the mower off the lawn and minimize the number of turns you make with the mower.
- Don’t remove more than a third of the grass blade in one mow.
After the first mow, cut back on frequent shallow watering, and switch to watering a couple of times a week, deeply. Water 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 eight weeks, your lawn should be well-established. Hit it with a little more fertilizer to encourage deep roots, and take down your “Please keep off the new grass” signs; your new lawn is ready for fun.
It’s unlikely that grass seeds will grow on top of flat, bare soil. The seeds may germinate but the roots won’t be strong enough to penetrate the soil. It’s best to rough up the soil before sowing for the best seed-to-soil contact.
Don’t cover grass seed with topsoil. The seed needs light to germinate. To protect the seed from birds and washing away, use straw (weed-free) or an erosion-control blanket.
Expect to see tiny grass blades in 10-14 days. Other varieties of seed may take up to 30 days.
DIY or LSE (Let Someone Else)?
Some homeowners and renters love being weekend warriors, but some of the rest of us prefer anything else.
If you’re like me, and you would rather reap the rewards of great grass someone else sowed and mowed, consider hiring a lawn care pro. Give them a call early so they can begin testing and sowing seeds at the proper planting time for your area.
* Editorial Note: LawnStarter participates in the Amazon Services LLC Associates Program, an affiliate advertising program. LawnStarter may earn revenue from products promoted in this article.
LawnStarter writer Penny Warner updated this article.
Daniel Ray is LawnStarter.com’s former editor in chief. He is an award-winning writer and editor who previously was editor in chief of the personal finance websites Bankrate.com and CreditCards.com, but with 30 years of gardening experience, he’s well qualified to help consumers grow a different kind of green.
Yard work at the click of a button.
As seen in Forbes, CNBC and USA Today, LawnStarter makes it easy to schedule service with a local lawn care professional.
Get a quote in minutes.
Manage everything online.
Enjoy your beautiful lawn.
Do you want a
Get easy-to-understand, actionable yard tips that will give you the greenest grass on the block.
How To Grow A Grass Lawn Without Weeds
Growing a lawn without weeds is a dream for many homeowners. While it’s probably unrealistic to have a lawn 100% free of weeds, you can aim to grow a thick, healthy stand of grass. That’s actually the easiest way to give weeds the brushoff: grow turf that’s so thick and strong that weeds can’t find an inch to take root. Follow this checklist to grow your healthiest grass ever.
Grow the Right Grass
Different grasses grow in different areas of the country. Warm-season grasses are usually grown in warmer, more southerly regions. Types include Bahiagrass, Bermudagrass, St. Augustinegrass and Zoysiagrass. Cool-season grasses are typically grown in cooler, more northerly regions. Types include Fescue, Kentucky Bluegrass and Ryegrass. Check with your local Cooperative Extension System office to learn which types of grass grow best in your area.
Start by cutting grass with a sharp mower blade that cuts grass cleanly, without tearing or shredding. Proper mowing height depends on grass type. Vary your mowing pattern to avoid creating ruts in the lawn. Avoid mowing when soil is wet, or you risk tearing up grass and soil.
Provide adequate moisture to grass, especially during episodes of drought or high temperatures. Provide deep, infrequent irrigation, which promotes healthy, deeper roots. Learn about lawn irrigation basics and how much grass actually needs.
Before you start a fertilizer program, do a soil test so you know you’re applying the correct blend of nutrients. In some parts of the country, soils may be acidic or alkaline and require additions of iron, magnesium or lime. Also, different types of grass need to be fertilized at different times of the year. Check with your local Cooperative Extension System office for help developing the right fertilizer program for your lawn.
Scout for Problems
Like any landscape planting, lawns can suffer from a variety of problems. Weeds, bare spots, insects and diseases can weaken and, if left untreated, even destroy a healthy lawn. Keep an eye out for problems in your lawn.
- Deal with weeds when you first see them, because one weed leads to many more. Learn about the types of lawn weed killers and when to use each. Discover why fall weed control is key and how to do it successfully.
- When a bare spot appears, figure out the cause and deal with it. Open soil extends an invitation to weeds, so repair bare spots as quickly as possible.
- Scout for insect problems. Some of the signs to look for are skunks digging up lawn or flocks of birds feeding on turf. White Grubs are a common lawn pest. Discover the basics of dealing with Grubs.
Aerate and Dethatch
Compacted soils don’t allow air and water to reach grass roots, which results in unhealthy grass.
Aerating helps relieve soil compaction.
When thatch builds up in a lawn, it can prevent water and fertilizer from reaching soil and provide refuge for insects.