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.
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.
how long after overseeding before weed & feed?
I live in a 5b zone–just aerated, fertilized, and overseeded this weekend. Can I use weed-control winterizer in a couple weeks (before the winter snow), or should I wait until spring before spreading weed-control?
I know that weed control too soon after aeration/overseeding can stunt germination, but I could possibly wait until early December (or a bit later, if it stays mild) to spread the weed&feed winterizer. Thoughts?
All the products I use say to wait at least a month. Personally I wait long until the new grass is well established. You can always get very aggressive with weeds in the future at any time, but you can only plant grass twice a year.
Excellent advice–thank you!
Without seeing pictures to see how bad your weed problem is, it might be hard to tell you 100% what your best course of action is, so I'll assume your yard is in pretty good shape with some occasional weed problem areas. This is a two part answer so bare with me:
-Don't use a weed and feed right now(or at all if you can help it). Wait until grass stops growing for the year and apply any fertilizer high in N but not with weed control. Weeds will die off during the winter months. This shot of fertilizer will kick in during the spring when your grass starts to grow again.
-In Feb/March when soil thaws and soil temperature is in the 50's, apply a pre emergent (preferably without fertilizer) to help keep weeds from growing.
So, if done right, your grass will kick into gear in Spring using the nitrogen from your winter application and most weeds will not be able to grow again from the pre emergent. As the season progresses, cut your grass high to crowd out weeds and spot spray any weeds that come up as summer goes on.
This is extremely helpful! And yes, I think (or at least thought) my yard was in pretty good condition (have only lived there through two springs), but this summer got hammered with weeds, crabgrass, creeping charlie, and super-heavy thatch. I have no idea why everything got so bad, but I suspect it was because: 1) I haven't used any fertilizer or weed control since I moved in (just aerated, overseeded, and fertilized this weekend for the first time) and 2) I used a mulching push-mower, which while good for reintroducing nutrients of clippings into the lawn, probably created more problems from also mulching the increasing weeds.
So yeah, I think I'm going to do just as you said: add a fertilizing step without weed control before winter. I really hope to re-gain control of this lawn (it's an old lawn, only one owner since the 50's), and wish that I hadn't skipped out on fertilizing/weeding these 1st two years. Hopefully the aeration/overseeding/fertilizing treatment I'm giving it now will make a difference for next year.