Garden Guides is the ultimate resource for cultivating your green thumb. Understanding when and how to fertilize your lawn can help you and your grass stand out from the rest. After overseeding your lawn, apply a lawn starter fertilizer to provide grass seedlings with the nutrients they need to establish themselves. Do not
How Many Days Do You Have to Wait Before Seeding After Weed & Feed?
You want a beautiful lawn for your family to enjoy, but it’s no longer enough to just mow it. You have to fertilize, water, kill weeds and then reseed any bare spots. Using a weed and feed product saved you some time, so now you’re ready to plant some grass seed. You may have to wait a bit longer, though, depending on the type of weed and feed product you used.
Weed and Feed
Weed and feed products consist of fertilizers such as nitrogen or potassium, and a pre-emergent or post-emergent herbicide. If the weed and feed is designed for spring application, it contains a pre-emergent. If it is designed for later in the growing season, it incorporates a post-emergent herbicide. Knowing which one you are using is important because the herbicides affect plants in significantly different ways.
- You want a beautiful lawn for your family to enjoy, but it’s no longer enough to just mow it.
- Using a weed and feed product saved you some time, so now you’re ready to plant some grass seed.
How They Work
Pre-emergent weed and feed is applied in early spring so the herbicide is in place before the undesirable weeds germinate. Pre-emergent herbicide works by inhibiting germination. It must be watered with at least one-half inch of water to move the chemical from the surface into the soil. Post-emergent herbicides, however, must be applied while the weeds are actively growing because for the chemical to work, the herbicide must be absorbed into the plant.
Why You Wait
Since weed and feed products are designed to prevent germination — or to eradicate a living plant — they can, for the most part, have a similar effect on young turf grass. The only exception is the pre-emergent herbicide siduron, which is actually used to assist in seed germination. When using a pre-emergent that does not contain siduron, wait a minimum of two months before seeding. If using a product designed for broadleaf weeds, read the label carefully, because the active ingredient in these post-emergent herbicides have a wider range for the waiting period. Grass can be planted in as little as one month after application for products using 2,4-D to as much as six months for atrazine-based products.
- Pre-emergent weed and feed is applied in early spring so the herbicide is in place before the undesirable weeds germinate.
- Post-emergent herbicides, however, must be applied while the weeds are actively growing because for the chemical to work, the herbicide must be absorbed into the plant.
Proper Seeding Methods
When you are ready to seed your lawn, use a garden rake to remove debris and to break up the surface to ensure the seed comes into contact with the soil. Broadcast the seeds in two directions to ensure complete coverage, and water the ground lightly and often for up to two weeks — keeping the soil moist. Once seedlings have established, gradually reduce the frequency of the watering, but lengthen the amount of time per watering. This will encourage a deep root system for your grass.
When and How to Fertilize Your Lawn
In some ways, lawns are a lot like people. Operating at the peak of beauty and performance requires a good diet and proper care. Lush, thick, green lawns depend on properly timed, properly balanced nutrition to look and grow their best. Understanding when and how to fertilize your lawn can help you and your grass stand out from the rest.
Starter fertilizers help your new seed or sod get started right.
When and How to Fertilize New Grass
If you’re starting a new lawn from seed, sod or plugs — or you’re doing bare lawn spot repair — a starter fertilizer helps grass get the perfect start. Unlike established lawns, new grass benefits from extra phosphorus, an essential plant nutrient that supports strong, deep roots. Some states only allow phosphorus-containing lawn fertilizers on new grass, so check with your county extension office if you’re unsure.
On fertilizer products, phosphorus is the middle number in the N-P-K ratio — usually “0” in normal lawn fertilizers. But with Pennington UltraGreen Starter Fertilizer 22-23-4, you get an ideal ratio of nitrogen, phosphorus and potassium, plus other essential lawn nutrients, including iron for deep green color. This premium fertilizer blend starts feeding new grass immediately and keeps feeding it for up to three months.
Always follow guidelines for the best time to plant grass seed for your region and grass type, then fertilize accordingly. For seed or plugs, apply fertilizer with a regular lawn spreader before you plant. If you’re starting a lawn with sod, fertilize after your sod is in place.
With any new lawn area, avoid using crabgrass preventer fertilizers or weed & feed fertilizers within four weeks before planting time. After seeding, wait until your new grass gets established and you’ve mowed your lawn at least three times.
Weed & feed fertilizers kill tough weeds and feed your lawn.
When and How to Fertilize Established Lawns
To keep your existing lawn looking its best year-round, choose a fertilizer plan that meets its changing seasonal needs. At Pennington, we make it simple for northern and southern lawns. Just follow our four-part annual lawn fertilizer program:
Part 1 – Early Spring
Between February and April, temperatures warm and weed seeds start to germinate. Prevent new weeds — and feed your lawn in the process — with Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III 30-0-4. You can stop new weeds before their roots get established and control new weeds for up to five months.
Timing is critical for this step. Make sure it’s applied before crabgrass seed germinates — that happens when soil temperatures reach 55 degrees Fahrenheit. For best results, apply with a spreader to actively growing turf and give your lawn at least .5 inch of water from rainfall or irrigation within 14 days.
On top of weed control, Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III 30-0-4 delivers iron and fast-acting nitrogen for immediate greening, and slow-release nitrogen for extended feeding for up to three months. Always follow the label instructions for your specific grass type. Do not apply this product within 60 days of overseeding. Wait until the following year before treating new sod.
Part 2 – Late Spring
Between April and June, existing weeds launch into active growth. Weed & feed fertilizers combine broadleaf weed killers with nutrients to feed your actively growing lawn:
treats northern and southern grasses to kill more than 250 weeds from tip to root. It feeds your lawn essential nutrients for thick growth and rich color. Plus, it keeps feeding for up to three months. , designed especially for southern lawns, kills tough existing weeds* and keeps controlling new weeds for up to three months. And while it does that, this product keeps feeding your lawn the essential nutrients it needs.
Always check weed & feed labels for your specific grass type and follow instructions carefully. Weed & feeds are most effective when weeds are young and small. For best results, apply the product in the early morning when grass is wet with dew and no rain is forecast for one to two days.
If you plan to overseed, avoid weed & feed for four weeks before. After overseeding, wait until your third mowing occurs. For sodding, sprigging or plugging, wait four weeks before you weed & feed so new grass can start without delay.
Part 3 – Summer
Between June and August, proper feeding helps strengthen lawns against heat and drought. Keep your lawn beautiful and resilient with Pennington UltraGreen Lawn Fertilizer 30-0-4. This premium lawn fertilizer, ideal for northern or southern lawns, keeps feeding for up to three months. Your lawn gets essential nutrients, including iron for rich color, and you get thick, lush green grass.
Always check the label for your specific grass type, then follow instructions accordingly. Used as directed, you can apply Pennington UltraGreen Lawn Fertilizer 30-0-4 to wet or dry lawns and not worry about fertilizer burn.
Part 4 – Late Summer to Late Fall
Between August and November, grass slows down and prepares for the winter months. At the same time, broadleaf weeds start active growth again. With Pennington UltraGreen Winterizer Plus Weed & Feed Fertilizer 22-0-14, you can feed your northern or southern lawn nutrients essential to its winter prep and spring green-up — and kill broadleaf weeds. As a general rule, allow six to eight weeks between fertilizing and your first expected frost.
As with all fertilizer products, check the label and follow instructions for your specific grass type. If you’re overseeding, wait until next year for weed & feed. Instead, turn to Pennington UltraGreen Lawn Fertilizer 30-0-4 for the year’s final feeding.
Always sweep excess fertilizer off sidewalks and patios to avoid runoff.
How to Apply Lawn Fertilizer for Best Results
Whenever you apply fertilizer, always follow best practices for fertilizer safety. For best results, mow your lawn one to two days beforehand. Then set your spreader to the setting recommended on the product label.
- For drop spreaders, start with two strips across your lawn’s ends. Then work back and forth, overlapping each swath slightly.
- For broadcast spreaders, start on the outside and work in, overlapping slightly as you go.
Always shut the hopper when you stop and turn to prevent a fertilizer pile. When finished, sweep excess fertilizer off hard surfaces, such as sidewalks and driveways, to avoid iron stains and fertilizer runoff.
By following these lawn fertilizer tips, you can keep your grass at the peak of performance, beauty and health. At Pennington, we take pride in providing you with the best in lawn fertilizers and expert advice to help you have a lawn you’re proud to own. Stay connected with our email newsletter for accurate, timely tips and offers to help you make the most of your lawn and home.
*dollarweed, clover, henbit and chickweed
Always read product labels thoroughly and follow instructions, including specific guidance for your grass type.
Pennington is a registered trademark of Pennington Seed, Inc.
UltraGreen is a registered trademark of Central Garden & Pet Company.
What Fertilizer to Use After Overseeding [5 Tips to Feed Grass Seed]
After overseeding your lawn, apply a lawn starter fertilizer to provide grass seedlings with the nutrients they need to establish themselves. Do not substitute lawn starter with a fertilizer meant for mature grass. Mature grass fertilizer doesn’t contain the nutrients new grass needs to develop roots. Similarly, avoid using “weed and feed” fertilizers. These products will kill your grass seedlings.
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5 Tips for Fertilizing Your Lawn After Overseeding
Overseeding a lawn takes time and money. Naturally, you want to get the most out of your efforts. In order to ensure your grass seedlings survive and thrive, it’s essential to follow the proper methods. Employ these tricks to make sure your grass seed roars to life.
Use a Lawn Starter Fertilizer
A lawn starter fertilizer is formulated so that of the three main ingredients in fertilizer (nitrogen, phosphorus, and potassium) phosphorus is the most abundant nutrient. This is important because phosphorus drives grass root growth. A lawn starter fertilizer will encourage your grass seedlings to take root quickly. This will make them hardy and established, whether you overseed in late spring or fall.
- Use this lawn starter fertilizer for new grass seed.
- Lawn starter fertilizer has high phosphorus content to promote seedling root growth.
- Do not use a fertilizer designed for mature grass. These often contain little to no phosphorus.
A standard fertilizer used for established lawns does not make for a good lawn starter. These formulas contain very little phosphorus because mature grass has already established roots. Some fertilizers for established warm-season grass lawns even contain no phosphorus at all. If you don’t use a lawn starter fertilizer on your seedlings, they won’t develop strong roots and may die.
- Great starter fertilizer for new seed or sod.
- You can also use Pennington UltraGreen for overseeding or on an existing lawn.
- 5% Iron promotes a deep, thick, lush lawn.
Avoid Weed and Feed Products
Weed and feed products are a death knell for grass seed. This is due to the fact that most weed and feed combines fertilizer with pre-emergent herbicide. This type of herbicide attacks all types of plant seeds, killing them as they germinate. If you spread weed and feed on a lawn that has been overseeded in the past 8 weeks, it can kill all the grass seedlings there.
- Weed and feed products contain pre-emergent herbicides that kill grass seeds as they sprout.
- Do not apply weed and feed to a lawn that has been overseeded in the past 8 weeks.
- Do not overseed if you have applied weed and feed in the past 12 weeks.
The herbicide in weed and feed is designed to linger in the soil for up to 3 months. If you have already applied weed and feed, don’t overseed your lawn for at least 12 weeks. The herbicide in the soil will attack every type of grass seed.
Dethatch Before You Overseed
A thick layer of thatch forms a barrier between the grass and the soil. If you spread grass seed on a lawn with heavy thatch, the seed will not reach the soil. Without soil contact, your grass will not sprout and establish itself. Check the thatch layer in your yard and dethatch if necessary before seeding.
- Thick thatch prevents grass seed from reaching the soil where it can root.
- Rent a dethatcher or power rake to remove thatch buildup before overseeding.
- Thatch soaks up water and fertilizer, robbing nutrients and moisture from the soil and grass seed.
In addition to preventing your grass seedlings from taking root, thick thatch also acts like a sponge, absorbing water and fertilizer before it can penetrate the soil. Fertilizing on thick thatch will be far less effective. Removing thatch prior to overseeding helps you deliver more lawn starter fertilizer to your grass seeds.
Aerate Your Lawn
Compacted soil makes it difficult for grass seedlings to take root. Not only that, but fertilizers have a difficult time penetrating hard soil. It’s a good idea to aerate the soil so that it absorbs fertilizer and feeds your grass seeds.
- Hard soil prevents grass seeds from rooting.
- Compact soils struggle to absorb nutrients from fertilizer.
- After dethatching, aerate your soil to make feeding your grass seed easier.
Aeration goes hand-in-hand with dethatching. A recently dethatched yard is ripe for aeration. If you mow, dethatch, and aerate, your entire lawn is in the perfect condition for overseeding.
Boost Seed Growth with Compost
Compost is an excellent natural fertilizer, but there’s one catch—the nitrogen in compost is contained in uric acid, and uric acid evaporates quickly when exposed to light. So, a thin layer of compost spread over your lawn will quickly lose most of its fertilizing power. There is a solution though. If your lawn was recently aerated it has thousands of tiny holes. You can spread compost over a recently aerated lawn to fill these holes and inject nitrogen-rich fertilizer into the soil.
- Compost is a great natural fertilizer that boosts grass seed growth.
- Only spread compost on your lawn if it has recently been aerated. Compost will retain more of its nitrogen content when it is used to fill aeration holes.
- Rake a thin layer of compost over your grass seeds—it may lose most of its nutrients but it will serve as a protective layer to keep seeds moist and safe from birds.
It’s a great idea to spread compost after aerating and overseeding. The compost will fill the aeration holes to funnel nutrients in the soil. Excess compost on the top of your grass seeds will keep them protected from drying out.
Is it OK to Fertilize After Overseeding?
It is perfectly safe to fertilize after overseeding your lawn. In fact, applying a specialized lawn starter fertilizer will increase the number of grass seedlings that survive to adulthood. For best results, apply a starter fertilizer within 3 days over overseeding. This will contribute to a lush lawn.
When Can I Fertilize My Lawn After Seeding?
If you’ve recently overseeded your lawn, there’s no reason to wait to apply fertilizer. The sooner you spread a lawn starter fertilizer on your yard, the sooner it will begin to feed your grass seedlings. If you like, you apply fertilizer the minute you’re done spreading your grass seed.
Do You Fertilize Before or After Seeding?
You can fertilize your lawn before or after overseeding. Both tactics work to feed your new grass seed. It’s best to fertilize within 3 days of seeding. This means you can spread your starter fertilizer a few days before you lay down your seed or a few days after. Both are far more beneficial for a healthy lawn than going without fertilizer.
Can You Put Fertilizer Down With Grass Seed?
If you want to make your seeding and fertilizing processes more efficient, you can spread your grass seed and lawn starter simultaneously. Simply measure out the correct amount of seed and fertilizer for the square footage you are overseeding, mix the fertilizer and seed thoroughly, and add them both to this lawn spreader. Make sure to spread the seed and fertilizer evenly across your lawn, following an east-west pattern followed by a north-south pattern for proper coverage.