Between winter snow, spring mud, and sweltering summers, the weather of the northeast can play havoc on even the best-cared-for lawn. This can result in dead grass, bald patches, and poor grass growth. But there is a solution to this! If you add overseeding to your lawn care schedule, you can return your yard to the vibrant green glow you know and love.
Below, we’ll cover the benefits of overseeding as well as the best time to overseed your yard in the northeast. We’ll also cover the step by step process of how to overseed your lawn. We’re the experts so that you can reap the rewards.
Table of Contents
What is Overseeding?
Overseeding is the process of adding grass seed to a lawn that already has existing grass. Because the goal is to get new grass to grow among mature grass, specific steps must be taken when overseeding your lawn.
For best overseeding results, a lawn must be prepared thoroughly beforehand, with special care taken for growing conditions. Then, a proper seed blend for the climate should be distributed throughout the lawn. Following seed distribution, proper watering and fertilization schedules will ensure that new grass sprouts, grows to maturity, and returns your lawn to brilliance.
Why Overseed Your Lawn?
Grass, like all organisms, does not live forever. Grass naturally dies, weakens, or begins to grow poorly as it enters later stages of its lifespan. Even the best cared for lawn can fall prey to these cycles. But how can you tell your lawn needs overseeding? And what are the benefits of overseeding.
Signs Your Lawn Needs Overseeding
So, your lawn is looking a little run down. Maybe it’s yellowed, is growing weakly, or is being invaded by weeds. How do you know when to overseed your lawn, versus attempting other fixes such as fertilizer or weed killer?
Here are the telltale signs that let you know it’s time to overseed your yard:
- Lawn has recently suffered drought stress
- Grass is dull and lacks vibrance
- Lawn has not been overseeded in the past 4 years
- Brown patches or bald spots are appearing in your lawn
- Lawn is damaged from hard use and/or heavy traffic
Benefits of Overseeding Your Lawn
There are a number of results of overseeding that improve not only the look of your yard but the long-term health, making lawncare easier going forward. Overseeding is actually a money saver because it will cause you to spend less on fertilizer, weed killers, and pesticides going forward!
These are the top benefits of lawn overseeding:
- Makes your yard more drought-resistant
- Fills and eliminates dead or brown patches of grass
- Causes grass to grow more thickly, preventing invasive weed growth
- Newer grass seed blends optimized for your climate are more disease and insect resistant
- Makes your lawn more resilient to use and foot traffic
- Creates a more lush and evenly-colored lawn
Best Time to Overseed Lawn in Northeast
Overseeding tactics differ from region to region. In most southern and western states, lawn care experts overseed in the spring or summer for best results. But if you live in the northeast, overseeding is a little bit different.
Spring vs. Fall Overseeding
The trick to overseeding is to do so in a growing boom for the grass, enabling new grass to get a strong footing. In northeastern states, grass gets a strong growth period in fall, as temperatures begin to cool. This means fall is actually the best time to overseed in the northeast, since the cold-resistant grasses used in this climate will perform better if they are seeded after the peak of summer.
The Prime Time to Overseed
As a simple rule of thumb for northeasterners, if you overseed in late-August through early-September you’ll get good results. This timing is in the sweet spot to let those new grass seeds take advantage of the fall grass growth spurt, while at the same gives them enough time to mature and get ready for winter. Before the first snowfall, you’ll see your lawn transformed!
We know climates in the northeast vary by region. Coastal areas, such as New Jersey and Delaware are usually more temperate than the northern portions of states such as Maine, New York, Vermont, and New Hampshire. To help precisely time your overseeding, it’s recommended by the Turfgrass Water Conservation Alliance to overseed roughly 45 days before the first fall frost.
By overseeding 6–8 weeks before your average first frost, you will more precisely time your overseeding efforts and yield the best results. If you’re in a region that receives cold snaps in October, you may choose to reseed in early August. On the contrary, if the mercury doesn’t tend to dip in your neighborhood until November or December, you can wait until mid-September to overseed.
9 Tips when Overseeding Lawn in Northeast
Overseeding a northeastern lawn the right way boils down to three main stages: lawn preparation, adding the right seed, and ensuring those seeds sprout. If you follow these simple steps when overseeding, you’ll get the best results from your grass seed and enjoy a healthy lawn.
Contrary to standard mowing practices, before overseeding you want to cut your existing grass very short. Short grass will help sunlight reach grass seedlings, allowing them to grow to maturity. For northeastern grass varieties, set your mowing blade height to 1 ½ –2” to prepare your lawn adequately.
In addition to allowing more grass seeds to sprout, there is an added benefit to this one-time low mowing. Since you will need to halt mowing for 2–4 weeks after overseeding, this close-cut will keep your lawn from getting out of control in the meantime.
After performing your close-cut mowing run, get your rake ready. Choose a strong garden or thatch rake that will not only rake up grass clippings, but will also break up some of the thatch buildup in your yard. Thatch is a layer of dead grass that shoots above the topsoil. If it’s too thick, it serves as a barrier that sponges up water and keeps seeds from ever reaching the soil. Thick thatch will prevent grass seeds from ever sprouting.
Once you’ve thoroughly raked your lawn, bag the raked grass clippings and the thatch for garbage or as an additive to your home compost. Once they’ve broken down a bit, these elements can become a good addition to your homebrew fertilizer.
Aeration is one of the best bang-for-your-buck lawn treatments available. Whether you use a spike aerator or plug aerator (either type can usually be rented from a hardware or garden store) you will accomplish all of the following in one step:
- Decompact soil, allowing for better grass root growth and increased drought resistance
- Create small holes, perfect for protecting grass seeds and giving them a place to take root
- Break up thatch, which can choke out grass seedlings
- Allow nutrients from fertilizer and natural sources to enter the soil
If there is one step you shouldn’t consider skipping when overseeding your lawn, it’s aeration. The strong grass seedlings that follow and overall lawn health will save you in grass seed and fertilizer going forward, which will make up for the cost of aerator rental.
Top-Dress the Soil
Top-dressing soil is the act of adding compost or organic fertilizer on top of existing grass. Think of the top-dressing as the instant fuel that gives grass seeds a place to sprout and get the energy they need in the very first stage of life.
It doesn’t take a lot of material to adequately top-dress soil. If you want to know how to top-dress soil, the simplest rule is to make sure you aren’t burying your existing grass and depriving it of light, which could kill it. Add a small amount of soil, compost, or fertilizer to an area and rake so that a thin layer is spread among the grass. A small amount of grass coverage is okay, but when it comes to top-dressing, it’s better to apply too little than to add too much.
Choose the Best Grass Seed for the Northeast
Different grass species grow best in different climates. Some grasses will die outright if planted in the wrong region. The northeast boasts cool winters and humid summers, both of which are destructive to warm-weather grass varieties.
Additionally, most grass seed mixes on the market today boast an ensemble of grasses. This is a good thing! It makes your lawn more resilient to different water and shade levels throughout your yard, and because growing cycles differ slightly, you’ll have a green lawn for a greater portion of the year.
The best grass seed for the northeast include:
- Fescue: usually an upright fescue and a creeping fescue, for better lawn coverage. Fescues are also among the most shade-tolerant grasses.
- Kentucky Bluegrass: Bluegrass is one of the most cold-tolerant lawn grasses, meaning it can survive even the harshest winters.
- Perennial Ryegrass: Ryegrass is a real lawn-saver. It germinates faster than other cold-tolerant grass species, meaning it will take your lawn from dormant to green fastest in the spring. It also has a very strong draught and heat resistance, so it can withstand summer temperatures.
Now that you’ve done all the legwork, it’s time for the real deal: overseeding. A broadcast spreader distributes seed evenly over an area with minimal effort. There are several good walk-behind broadcast spreaders that will do a fantastic job overseeding your lawn.
Make sure to use the amount of seed per square foot recommended on the grass seed packaging. This will ensure the best results. In bald patches of the yard, feel free to double the recommended amount of seed to effectively re-seed those areas.
Set the Seeds
Now that you’ve got your seed spread over your top-dressing it’s a job well done, right? Not quite. Unprotected grass seed is easy pickings for opportunistic birds, so you’ll want to know how to keep birds from eating grass seed.
The good news is, you’ve already laid the groundwork for seed protection. That top-dressing you added? It’s not just a great headstart for the seeds, it can also act as a shield.
Use a garden rake to rake the top-dressing to cover the seeds. This will protect the seeds and get them into the proper conditions for germination. It will also help push seeds into the small holes you created while aerating, allowing them to take root. Don’t worry if some seeds are still uncovered or partially covered—if you’ve got the majority taken care of, you will have success with overseeding.
Now that your seeds are on the lawn and protected, it’s time to give them a growth boost. Apply a slow-release fertilizer to your yard. Look for a fertilizer high in nitrogen with a release cycle of 6–8 weeks. This will continually feed your grass seedlings as they mature.
Slow-release, high-nitrogen fertilizers can be found in standard and organic varieties at most home and garden stores.
This is the final ingredient, and a crucial one. While grass may be resilient when it’s mature, grass seedlings are more fragile. Most of all, they need water and a lot of it.
After seeding and fertilization, water once or twice daily until the new grass reaches approximately 3” in height. The goal is to keep the soil moist around the clock, allowing for root growth. Continuous watering will also soak your fertilizer down into the soil. Grass under these conditions sprouts fast! In 2–4 weeks, you should have a new crop of grass growing among the old, and your lawn will go from dull and sickly, to green and vibrant.
Things to Avoid when Overseeding Your Lawn
Overseeding costs money and time, neither of which you want to waste. You want as many grass seeds as possible to reach maturity. In order to make sure you get the best results from overseeding, beware of the following:
- If you’ve applied crabgrass preventer, wait at least 16 weeks before overseeding. Crabgrass preventer will also stop your grass seeds from sprouting.
- If you’ve applied broadleaf weed killer, wait 4 weeks before overseeding. These can also inhibit grass growth in some cases.
- Remember any weed and feed products you’ve used may have included crabgrass preventer, broadleaf killer, or both.
- Make sure to choose the correct grass seed type. Cold-weather grasses don’t grow well in warm climates and vice-versa. In the northeast, cold-resistant fescue seed blends are often the best choice.
- Overseed at the correct time. Spring might seem to be the obvious time, but you’ll find more success in the northeast if you overseed in fall.
- Don’t mow too soon. Wait 2-4 weeks after overseeding before you mow your new grass seedlings for the first time. Mowing too soon could damage or kill young seedlings.