Over-seeding is a great way to increase the density of your lawn by adding new seed — and it can even help improve your lawn’s existing color. Overseeding is useful whether your lawn has bare patches or has become thin and needs a little help; you can spread seed over the top to help grow thicker, more vibrant grass that is less prone to pests and disease. In this complete guide, we’ve explored everything you need to know about how to overseed a lawn properly – from how to prepare in the early stages to how you should be treating it afterwards.
What Is Overseeding?
Overseeding is when grass seed is spread over the established grass to fill in thin or dead spots in the lawn. Unlike seeding a new lawn from scratch, which requires a lot of preparation, overseeding creates the optimal growing environment for your existing grass to make it thicker, greener, and healthier. It’s commonly used to:
- Fix damaged or thinning lawns
- Add newer varieties of grasses for color and disease resistance
- Extend your season and create a more vigorous turf
- Dense grass and an increased few of invasive weeds prevention
When Is the Best Time to Overseed?
The best time to overseed will vary depending on the type of grass you have and on your climate:
Cool-season grasses (like Kentucky bluegrass, fescue, ryegrass): Early autumn is optimal when soil temperatures are still warm but the air is cooler. You can transplant in the spring but any weeds will compete with the onions.
Warm-season grasses (Bermuda, zoysia, St. Augustine): Best time is late spring to early summer, when soil temperatures reach 65°F or more.
Timing the over-seeding properly allows seeds to germinate and develop strong roots before harsh weather sets in.
How to Overseed a Lawn
Overseeding means spreading new grass seed over an existing lawn, to fill in bare patches, to make a lawn more lush, or to prevent problems such as crabgrass. It takes a little care to get the seeds to germinate and grow. When performed correctly, overseeding rejuvenates your lawn, leaving it thicker, greener and healthier for greater resistance to disease, insects, and drought.
Assess Your Lawn
Begin by observing your lawn to determine where there are thin, bare or damaged patches. To figure out how much seed you will need, measure the size of your lawn.
Mow and Rake
Mow the lawn shorter than usual (to around 1.5 to 2 inches) so the seeds have improved soil contact and more light. Thoroughly rake the lawn to help pick up debris, old dead grass, and any thatch offenders that may inhibit seed-to-soil contact.
Aerate the Soil
Aeration pokes holes in the compacted soil, opening a path for oxygen, water and nutrients. I’d definitely suggest you aerate before overseeding, especially if you have a lawn that receives heavy traffic or you’ve got some heavy clay soil.
Choose the Right Grass Seed
Choose a grass seed mixture that will work with your current lawn and the climate. For lawns that remain green all year, mixtures of perennial ryegrass, Kentucky bluegrass and fine fescue are typical. For warm-weather grasses, opt for Bermuda or zoysia strains.
Spread the Seed
A broadcast spreader is one I like because it spreads really well, and you can achieve nice coverage with it. Sow at the directed seed rate for the packet, paying particular attention to any bare areas. Avoid the problem of over-seeding and having too many seeds grow.
Fertilize
Use a starter fertilizer high in phosphorus to help promote good root growth. Refrain from using high-nitrogen fertilizers at this point because they encourage leaf development at the expense of root growth.
Water Properly
Maintain a consistently moist soil, but not waterlogged. Keep the soil evenly moist 2-3 times per day, and reduce frequency once the seedlings are established and increase the depth to promote drought tolerance and deep rooting.
Maintain Your Lawn
Newly seeded spots no heavy foot traffic. Then, only when the grass reaches about 3 inches high, resume regular mowing, taking off no more than one-third of the length of the blade at a time.
Overseeding vs Reseeding: Major Differences
The primary distinction between overseeding and reseeding is the condition of your current lawn and the degree of damage it suffers:
Overseeding is the application of grass seed over an existing, mostly healthy lawn to help improve its density and appearance by allowing the new grass to fill in thin or sparse areas. You don’t have to take away from the grass that is already there, and it is less work.
Reseeding is the process of sowing new grass seed in an area from which dead or very damaged turf has been removed; it is basically growing a new lawn. It’s a must if you have lots of dead, brown areas on the lawn due to old fields and soil prep.
| Aspect | Overseeding | Reseeding |
| Lawn Condition | Mostly healthy with minor thinning | Severely damaged or mostly bare |
| Soil Preparation | Minimal (mowing and light raking) | Extensive (removal, tilling, amending soil) |
| Purpose | Improve density, introduce new grass types | Restore lawn from scratch |
| Time and Effort | Less time-consuming and easier to do | More labor-intensive and time-consuming |
| Risk of Failure | Lower, as existing grass supports growth | Higher, due to starting fresh |
Can You Overseed and Reseed Together?
Overseeding and reseeding are separate procedures, although in some cases they can be done in combination with each other to good effect. For instance, you might want to reseed large bare or damaged patches at the same time you overseed the healthier parts of your lawn to increase overall density. But reseeding is more of a fresh start than overseeding is: You prepare the soil and start from scratch, so it’s typically not done in combination with overseeding. Implementing both of these seeding approaches takes some strategic planning to make sure you don’t overseed or ruin your established grass when you prepare the soil.
Overseeding Tips for Success:
- Have your soil tested before overseeding in order to make pH and nutrient adjustments as necessary.
- Don’t over-seed in drought or hot weather, it will just be seed waste.
- A seed starter mulch, or a soil conditioner, can be used to keep seeds covered and ensure moisture.
- Kill weeds before overseeding to minimize competition.
- Be patient — some types of grass will take 2-3 weeks to sprout up completely.
Common Mistakes to Avoid When Overseeding
- Omitting aeration, which loosens the soil and increases seed-to-soil contact
- Seeding too densely causes a lack of air flow and disease
- Irregular watering, leading to seeds that dry out or rot
- Planting with grass seed that doesn’t match your warren’s existing lawn
- Disregarding soil preparation and fertilizing requirements
Conclusion:
Overseeding your lawn is a cost-effective way to breathe new life into it, increase its density, and support its overall health. Through the proper method — from evaluating your lawn and preparing the soil to choosing good-quality seed and taking good care of it — you can be assured of a lush, green front yard that will hold its own against weeds, pests and the environment. Whether you’re trying to repair bare spots or just want it to be fuller, knowing how to overseed a lawn will get you to your turf target.
FAQs
The majority of lawns will benefit from overseeding on a 1-3 year schedule, depending on wear and grass type.
It is usually not advisable to overseed during the summer since new seeds will take a hit under heat stress and will germinate very poorly (é”™)?—especially cool-season grasses.
It usually takes 7-21 days depending on the type of grass seed and on the environmental conditions to germinate.
Yes, a starter fertilizer with phosphorus will quickly develop young roots.
Weeds must be managed prior to overseeding, since they will compete with grass seedlings for nutrients and water.
