After a long, harsh winter in the Northeast, it’s common for homeowners to discover signs of lawn damage such as matted turf, snow mold, thinning grass, or exposed soil. The urge to repair these areas immediately is understandable — especially as warmer days hint at the growing season ahead. However, spring lawn seeding requires careful timing and planning, and understanding the risks before planting can help protect your investment and lead to stronger, more sustainable results.
While spring seeding can be successful, it also presents challenges we think you should be aware of. Soil conditions are often saturated from snowmelt, existing turf may still be dormant, and young grass plants must race to mature before summer heat and weed pressure arrive.
Here at Fairway Green Inc., we often remind homeowners not to judge their lawn too quickly in the spring. Turf typically looks its worst coming out of winter. So, before you plant, it’s important to evaluate whether seeding is truly necessary and whether spring is the right time.
How to Decide if Spring Seeding is Necessary
Not every lawn requires seeding simply because it looks thin in March.
Early spring turf is often soft, pale, and lacking rigidity as it transitions out of dormancy. However, areas of exposed soil with little to no grass will not likely bounce back and should be addressed to prevent erosion and further turf loss.
Spring seeding is most appropriate when:
- Bare areas are clearly visible
- Turf loss represents a meaningful portion of the lawn
- Soil is stable enough to support germination
In our experience, homeowners should approach minor thinning of their lawn with patience. Many lawns can naturally fill in once soil temperatures rise.
Is it OK to Plant Grass Seed in the Spring?
Although a lot of people associate the spring with planting grass seed, our years of experience show that most spring seedings do not last through the summer. That being said, planting grass seed in the spring is achievable, but it requires careful timing and maintenance. Based on the individual lawn conditions you are facing it might be unavoidable to wait until the early fall (the ideal time to seed in our area is late August through September). It is important to understand that success depends largely on establishing the new turf before summer stress and weed competition intensifies. It is also important to have realistic expectations of how the new grass seed will perform throughout the entire season.
We strongly recommend partnering with our team or your local lawn care professional when making this decision. Spring seeding is a balancing act which requires careful coordination of treatment timing and proper seeding practices. Did you know that your spring pre-emergent and weed control can impede new grass seed from germinating? We do! If you have questions about bare areas in the lawn this spring – Give us a call!
Factors Influencing Spring Planting Decisions
Several risks should be evaluated before moving forward:
- Summer heat can damage immature turf
- Weed competition is significantly higher in the spring
- Preventative crabgrass treatments cannot be applied to newly seeded areas
- Weed control can not be applied until the grass has matured and been mowed at least 3 times
Because of these limitations, spring seeding is often best reserved for targeted repair work rather than full lawn renovations.
Spot Seeding
Filling in small bare areas of your lawn is more achievable in the spring than seeding large sections. This might be a compromise to help improve your lawn’s density while having patience to do larger seeding projects at the end of Summer. All the recommendations to follow will also apply to seeding small areas. You should always communicate your seeding plans to your lawn care team. Coordination is needed to avoid applying weed control in areas you plan to seed.
When to Plant Grass Seed in the Spring
Optimal Timing for Spring Seeding
Plant grass seed in spring as early as the weather permits, ideally between late March and early April in the Northeast as long as soil temperatures are warm enough for germination (we will cover more details on this in the following section). The primary goal is to give new grass the maximum amount of time to establish before the summer heat arrives. Young plants with shallow roots struggle when temperatures climb, so earlier is almost always better.
Ideal Soil and Air Temperatures
Successful germination depends heavily on temperature.
- Soil temperatures: consistently 55°F–70°F
- Daytime air temperatures: ideally 60°F–75°F for cool-season grasses
Cold soil temperatures is one of the main reasons that spring seeding projects in our area are unsuccessful in the long term. By the time the soil is warm enough for the seed to germinate, there’s only a small window of time before the summer heat kicks in. Summer heat is the most stressful time on a cool season grass plant, asking an immature plant to survive that stress is a big ask. This is why we get phone calls each year stating that the new seed looked great in May, but by August it was mostly gone and overrun with weeds. The immature plants can’t handle the stress or compete with the summer weeds.
What Grass Seed to Plant in the Spring
Cool-Season vs. Warm-Season Grasses
In New Jersey and much of the Northeast, cool-season grasses such as Kentucky bluegrass, ryegrass, and fescues dominate residential lawns. These varieties thrive in cooler temperatures, making early spring a workable — though not ideal — planting window.
Warm-season grasses prefer much hotter soil and are typically planted later in the year, but they are far less common in this region.
Key Considerations for Spring Seeding
How to Seed
There are multiple avenues for seeding, but the right choice will depend on whether you’ve had any treatments applied to your lawn.
- If you’ve already had a treatment that includes crabgrass pre-emergent, the only option is to add 2-3 inches of topsoil to the areas that need seeding. The crabgrass pre-emergent will impede germination, so adding the topsoil will allow the seed to germinate without it coming in contact with the pre-emergent. After adding the topsoil, you can then seed into the topsoil and lightly rake it all together to get good seed to soil contact.
- If you haven’t had any treatments, then you can seed into your existing soil. That being said, you can’t just dump seed on top of the ground and expect it to work. Just like a farmer tills his field before planting, you need to loosen up and disturb the soil before adding seed. This can be done by raking, tilling, or aerating, all of these methods will open up the soil and provide good seed to soil contact for germination.
What to Do After Seeding
Immediately after seeding follow these steps to improve your chances of success:
- Keep the soil consistently moist with light, frequent watering *Water daily for 20 minutes per area. THIS IS THE ONLY TIME WE WILL EVER RECOMMEND FREQUENT WATERING. If you’re not seeding, don’t water every day!
- Avoid heavy traffic on newly seeded areas *Protect the area with stakes or markers if necessary to prevent foot traffic until the turf matures.
- Apply a starter fertilizer high in phosphorus to promote root development
- Delay mowing until grass reaches roughly 4 inches
- Inform your lawn care provider so herbicides are avoided
Young seedlings require immediate nutrition and protection — skipping these steps is a common cause of failure.
Watering New Grass Seed
Frequent rainfall often helps maintain moisture in the spring, but irrigation should supplement dry periods. Because new grass lacks established roots, light watering is far more effective than deep soaking. This type of water is directly opposite of our regular watering recommendations. While new grass needs frequent, light watering, it is important to go back to infrequent heavy watering once your new grass is established. For a detailed look at watering your lawn properly, check out our blog: Lawn Watering Schedule.
Treating New Grass with Lawn Care Treatments
Our recommendation is that your newly seeded areas must grow to at least 4 inches and be cut with a lawn mower at least three times before you can resume traditional herbicide and pesticide applications in that area. This is not only our recommendation, but it is also listed on most herbicide labels, treating new grass before that time period can result in a complete loss of all the work you just put in.
One of the most frustrating aspects of this topic is managing homeowners’ expectations that you CAN NOT treat new grass seed with weed control of any kind. For a more in-depth look at why, see below.
Challenges Newly Seeded Lawns Face in Spring
Summer Heat
The greatest threat to spring-seeded grass is simple: summer arrives quickly.
Just one week of temperatures above 80°F can injure immature plants that have not yet developed strong root systems. Heat waves in late spring are not uncommon and can shorten the establishment window dramatically.
Additionally, drought conditions and peak lawn disease activity occur during summer — both of which disproportionately impact immature turf.
Broadleaf Weed Competition
Spring is the prime growing season not only for grass, but also for weeds. Areas with thin turf expose more soil to sunlight, creating ideal conditions for broadleaf weeds to germinate. These are also the areas you would have just seeded! And as mentioned above, weed control products cannot be applied until the new grass has been mowed several times.
This forces homeowners into a difficult waiting period where weeds and turf mature together. Your newly seeded areas will have weeds, and you must wait to treat them. Reseeding in the fall might be necessary after the weeds have been killed and bare areas open up again.
Crabgrass Issues
Crabgrass presents one of the biggest dilemmas with spring seeding. The most effective way to manage crabgrass is with pre-emergent weed control. We apply these preventative treatments in the spring, but these products also prevent desirable grass from germinating. Seeded areas must therefore remain untreated, leaving them vulnerable.
By early summer, crabgrass can quickly overtake young turf. When treated later, the result is often dead crabgrass patches that require reseeding again in the fall.
Can You Still Prevent Crabgrass?
Over the years we have found that you can try to prevent crabgrass and also seed by following these steps:
- Apply several inches of fresh topsoil over areas treated with pre-emergent to create a barrier. Then seed into the new topsoil.
or
- Use pre-emergent products labeled safe for new seeds. We have tried and found these products are much less effective than traditional pre-emergent crabgrass control.
Common Mistakes When Planting Grass Seed in Spring
Seeding Too Late
Planting late reduces the time grass has to mature before summer stress. This often results in shallow roots and increased vulnerability to heat and drought. Unfortunately, we can’t control the soil temperatures so there are years where germination will take place right before the summer heat wave.
Neglecting Watering
New seed must remain consistently moist to germinate. Inconsistent watering is one of the most frequent reasons spring seeding fails. Every season we get asked to evaluate new seed that isn’t performing well and customers feel they are watering enough. It turns out they are almost always not. Their seeds are dry and will likely not germinate. You can not skip a day of watering before your new seed is established.
Applying Weed Control Prematurely
Preventative crabgrass products can inhibit new grass growth. Wait until the new lawn has been mowed at least three times before applying most weed controls.
I’m only including this next part because this is a real example that happened with a customer: Just going over the new grass with a mower does not count as mowing! The new plants need to be tall enough where they are actually being cut by the mower. To be fair, the customer had a company doing the mowing and they were there 3 times after seeding, but when I got to the property the plants were barely an inch tall and had never actually been cut by the mowers.
Why is Seeding Better after the Summer?
Weather remains the one variable no homeowner can control.
Late snowfalls, cool soil temperatures, sudden heat, and drought all compress the growing window and increase stress on young plants during the spring. Even when everything is done correctly, immature turf is naturally more susceptible to disease than established grass.
Because of these factors, we prefer late August through September for major seeding projects in our area. This is when weed pressure declines and cooler temperatures return. For more information, check out this blog: Benefits of Core Aeration and Overseeding. Still, when spring repairs are unavoidable, attentive care can greatly improve outcomes. If you are looking for more information on this topic or help with seeding your lawn this year, give us a call!
Call Fairway Green, Inc. at (908) 281-7888 to speak with our team, or request service online.
Frequently Asked Questions About Spring Grass Seeding
Q: Is it OK to plant grass seed in the spring?
A: Yes, but fall is generally the ideal season for cool-season grasses. Spring seeding requires closer monitoring to ensure the lawn establishes before summer.
Q: What is the best temperature to plant grass seed in spring?
A: Aim for soil temperatures between 55°F and 70°F and daytime air temperatures between 60°F and 75°F.
Q: Can I just throw grass seed down and it will grow?
A: Simply scattering seed rarely produces results. Proper soil preparation, seed-to-soil contact, fertilization, and consistent moisture are essential.
Q: Can I treat weeds if I seed?
A: NO, It is important to understand that you will not be able to treat weeds that are growing in your new grass seed until the new grass has been mowed at least three times. This is the most common frustration homeowners express about.