Weed and seed your lawn
Since releasing this year’s FREE Guide To Fall Seeding we have had some questions come about spraying weeds now leading up to the seeding. In and this blog post will answer those.
First off, you do NOT have to kill all the weeds. The winter is going to kill them for you and having a few here and there will not get in your way too badly. However, if you have had a big emergence of crabgrass in your lawn (where it is all you can see), you will want to try and knock that back some – mainly so it doesn’t go to seed on you.
It’s probably hard for you to tell, but this lawn here is in Munster, IN and this is 99% crabgrass.
Here is what it looks like up close:
If this is you, you will want to spray this and start knocking it down. Leaving it in there is good because it will help hold your seed in place but for sure, if your lawn is this thick with crabgrass, hose it good with quinclorac , quincept or mesotrione leading up to seeding following the recommendations below.
Note on Details:
I’m going to get highly detailed here because I respect you and your intelligence. You’re smart and therefore you can and should seek to understand these chems so you can get the proper result from using them and have no fear of them. I respect the fact that once you take the time to understand this example, you will be better at discernment of similar questions in the future and thus you will be more confident in your approach and strategy. In other words, I’m not going to talk to you like you’re dumb and just tell you what to do. Instead I’m going to teach you like a professional. I hope you are good with that.
Second, I respect the green industry and the lawn pros who make their living doing this day in and day out. When you use professional formulations of products like the ones listed here, I now view you on their level and that also means we need to stay within the bounds of the label which is the law. If you see YouTubers or social media influencers out there not following the label, including me, you should call them/me out. Everyone makes mistakes here and there, but it’s their reaction to being called out that truly shows their intent. I like to think everyone means well and is willing to admit when they are wrong.
Can I Spray Weeds and Kill Crabgrass Now if I Plan to Seed In September/Fall Time?
This is the most common question and it’s difficult to answer for all of you so I’m going to show you how to find the answer for yourself using 2 examples.
Reading The Label – Quinclorac 75DF
Key: The answer to your question is on the label. Labels of weed control products almost always tell you the wait time until seeding after application. Let’s look at two that you likely may be using.
First one is quinclorac . This is the first choice active ingredient that kills crabgrass that you may be seeing. If your lawn is covered in crabgrass like a carpet – especially through the middle or meaty part of the lawn, you will want to kill it off or at least stunt it really well before seeding.
The formulation most of you have is the “DF” which stands for “dry flowable” which means it’s small granules that you put in water to make a solution to spray. The concentration is 75% quinclorac.
Here’s the trick to reading labels fast. Find the PDF online. Make sure it is the VERY SAME product you have in hand. DoMyOwn is a great resource for this .
Once you pull up the label, hit “command F” on Mac or “control F” on PC and this opens up a search window. Type the word “Seed” in that window and it will reveal how many times that word appears in the label PDF.
Use the down arrows in that window to “scroll” through all the instances where that word appears. As I did this, I found the following very quickly.
So we can see that for certain types of seedings, this product won’t cause any harm at all but we have to scroll down to the tables 1 and 4 to get the details. Table 1 is going to tell us the grass types that are “highly” and “moderately” tolerant and table 4 will tell us the timing of the applications for ANY seeding.
This is where it sometimes gets confusing so follow along with me.
Here is Table 1
So what this is telling us is that you can use Quinclorac 75DF on established grasses listed as “highly” or “moderately” tolerant. That is really all this chart is for. It has nothing to do with seeding, hence the word “established.” But you still have to look at this chart first to find out if you should even use this product in the first place.
It’s main purpose is to tell you that you should not use this product on Bahia, Colonial Bent, Centipede or St Aug, period. Doesn’t matter if you are seeding or not, you should NOT use this product on these grass types. It also warns you about using it in or around fine fescues – they must be part of a blend if you do.
So in our case, where we are thinking about seeding the lawn, if we are planning to seed Bahia grass for example, then this product is out, 100%. No Bueno.
So if you passed the test on this part and are seeding Kentucky Bluegrass for example, then you need to next consult table 4 which is going to give you the timing of seeding both before and after.
Let’s stick with our example of Kentucky Bluegrass and you can see that it’s ok to apply quinclorac to the lawn to kill crabgrass 7 days before seeding or more. So right now, if you are let’s say 2 weeks away from seeding, you are welcome to spray away and kill that crabgrass dead. (note, this product turns crabgrass orange/red in about 6 days. But it takes much longer for the crabgrass to fully break down so likely some of it will still be there when you seed, just red and dead).
Also of note, if you have crabgrass living after or during your seed grow in, you have to wait 28 days after emergence (when you see it) before spraying. It’s important to understand what mix you are seeding in this case because if you have a tall fescue, bluegrass mixed seed , the tall fescue will emerge in about 10 days but the bluegrass won’t emerge for 18-21 days so you need to wait 28 days AFTER THE BLUEGRASS emerges before spraying quinclorac. If you really want to be safe, wait the 28 days and 1-2 mowings before applying – this adds some extra protection for the late bloomers as mowing encourages new grass to “harden off” quicker.
Reading The Label – Seeding and Tenacity – Mesotrione
( we have the generic which is cheaper FYI)I will throw this one in real quick because it’s a little different. We recommend this product for a pre-emergent application at the time of seeding. It will suppress certain weeds in your grow in. If you are new and inexperienced, DO NOT think you have to use this – your results will be ok without it. But if you do use it, people think they can just spray it anytime they want and this is not true.
You can spray it anytime you want leading up to seed day, and on seed day, but once your seeds germinate, you should NOT spray it again until the new gras has been mowed 2-4 times or 4 weeks whichever is longer.
So to be clear – you can apply this up to seeding, but once the seed germinates (4-5 days for rye, up to 21 days for bluegrass) you should NOT apply it to weeds until the new turf has been mowed 2-4 times or 4 weeks, whichever is longer. This is because baby grass is weak and can’t withstand/tolerate mesotrione .
Reading The Label – Speed Zone – Red Label
This is another weed control I have recommended heavily and they list right on the label in clear printing how long to wait until you seed. Keep in mind, this product has an 85F degree temp restriction anyway so many of you would not be using it in summer, but in case you did, here is the wait time after app before seeding:
Reading the Label – Quincept – New Farm
Ok now just as I make everything seem like it’s as simple as reading the label, NuFarm (who I love) comes in and just leaves it off their Quincept label completely . Maybe someone from NuFarm can Tweet me and let me know why y’all have left this off your label for so many years… is there a typo you have not corrected? I have read and read the label and this is all I can find – it’s all about “spraying after you seed” but nothing about “spraying before you seed.”
You can read that all you want, backward and forward and it only tells you about “after” seeding. And since I have recommended this weed control so heavily this year I feel like I need to provide an answer.
First off, when I worked for TruGreen ChemLawn, Quincept was our go-to weed control for summer and I remember that every year that right around 3 weeks before overseeding time we would get a memo telling us to cut off the Quincept use. The memo would come early but would read “stop spraying Quincept 2 weeks prior to starting your overseedings for customers.”
So that is my first clue as to the reseed window – it comes from my experience.
Next, I found a product that is similar to Quincept in that it has the same active ingredients plus one. That is Q4 Plus . It has very similar concentrations of the active ingredients within the Quincept plus one more. That product says this:
In short, if you are using Quincept, wait a minimum of 14 days after application to throw down your grass seed. I had to use some logic with this one and figured I’d share it just in case you are doing all the research and coming up empty. Now you know.
So there you go, all about reading labels for seeding – hope this has helped you and that your seeding will be successful this season!
Welcome to the official site of Allyn Hane, The Lawn Care Nut from YouTube. Here you will find my free newsletter that gives you much more than just the tip. I also carry the full line of N-Ext soil optimization products including RGS, Air8 and De-Thatch along with MicroGreen and Green Effect plus much more!
How to Restore a Lawn Full of Weeds
Read our handy guide on how to restore a weedy, patchy lawn to its former glory.
Share this story
- Share this on Facebook
- Share this on Twitter
Share All sharing options for: How to Restore a Lawn Full of Weeds
If your lawn is patchy and full of weeds, it will never be the envy of the neighborhood. What you’re after is a lush, green lawn with even grass and no dandelions poking their way through. That may sound hard to achieve, but it isn’t too difficult if you follow these steps.
If you only have a few pesky weeds punctuating your lawn, you may be able to dig them up by hand—paying careful attention to make sure you get them roots and all. But if your lawn is overrun with weeds, you may need to start from scratch. Here’s our how-to guide on restoring a lawn full of weeds.
Once your lawn is nice and green, we recommend hiring a professional lawn care company to help you maintain it to keep it weed-free. Our top recommendation goes to industry leader TruGreen.
Restoring a Lawn Full of Weeds in 10 Steps
Step 1: Identify the Weeds You Have
In order to make a successful game plan, you’ll need to know just what kind of weeds you’re dealing with. Weed treatments are designed to target specific weeds, so what may work on your broadleaf weeds may leave your grass-like weeds A-OK.
Weeds come in multiple categories, either broadleaf, grass-like, or grassy.
- Appearance: Broad, flat leaves
- Common types: Clover, ground ivy, dandelions, chickweed
- Appearance: Similar to grass, with hollow leaves in a triangular or tube shape
- Common types: Nutsedge, wild garlic, wild onion
- Appearance: Resembles grass, grows one leaf at a time
- Common types: Foxtail, annual bluegrass, quackgrass, crabgrass
Weeds can be broken down further into categories based on their life cycle—annual, biennial, or perennial.
- Annual: Produces seeds during one season only
- Biennial: Produces seeds during two back-to-back seasons
- Perennial: Produces seeds over many seasons
Step 2: Select a Proper Herbicide
Next, it’s time to select the proper weed treatment based on both weed classification and the stage in their life cycle. Pre-emergent herbicides tackle weed issues before they spring up. Post-emergent herbicides target established weeds.
Keep in mind that herbicides can kill whatever plant life they come into contact with—even if the label says otherwise—so handle with care. If your aim is to re-establish your lawn, as we recommend, killing your existing, thinning grass isn’t a big deal, since you will need to start fresh anyway.
Step 3: Apply the Treatment
For this step, it’s crucial that you follow the directions to the letter. Make sure you apply the proper product at the proper time. It’s a good idea to check out the forecast beforehand, since you don’t want any storms to wash away your herbicide.
Step 4: Wait It Out
How soon you can plant seed depends on the type of weed treatment you choose. Pre-emergent herbicides will prevent grass seeds from growing just as much as weed seeds, so it would be no good to sow seeds immediately after.
Depending on the type of weed treatment you choose, you may need to wait for up to four weeks. You can ask your local garden center for information about when it’s safe to plant.
Step 5: Rake and Till
Once the weeds—and grass, if applicable—turn brown, it’s time to bust out your rake. Rake up as much of the weeds as you can. Use your tilling fork to pull any extra weeds out and till the soil to prepare it for your amendments and seed.
Step 6: Dethatch and Aerate
Aerating your lawn can help break up thatch, the layer of decomposing organic matter between your lawn’s soil and grass blades. Thatch can be beneficial, since it can make your lawn more resilient and provide insulation from extreme temperatures and changes in soil moisture. But if it gets over a half-inch in thickness, it can cause root damage, including root rot.
Your raking and tilling from the previous step can help with dethatching, but you can also use a dethatching rake if the layer is too excessive.
Aeration improves your grassroots’ access to air, nutrients, and water. Use a spike or core aerator to break up the soil. If you use a core aerator, be sure to make two to three passes in different directions. Allow the plugs of soil you remove to decompose on top of your soil layer rather than remove them.
Step 7: Amend the Soil
Now, you can apply your soil amendment to ready your soil for the grass seed or sod.
Step 8: Lay Down Seed or Sod
You have a choice ahead of you. Do you want to lay down seed or sod? There are pros and cons to each.
- Pros: Less expensive, more variety
- Cons: Takes longer to germinate, can only lay at certain times of year depending on grass type
- Pros: Instant grass, can lay any time of year, requires little maintenance
- Cons: More costly, less variety in grass can mean less healthy lawn overall
To prepare the soil after either method, make sure you till it down to roughly 6 to 8 inches.
First, you need to choose the right type of seed for your lawn. That will depend on the region you live in—one that needs cool-season grasses, warm-season grasses, or a transition zone that allows more flexibility. After you determine which category you need, you can select specific grasses that may have attributes you’re after, like heat- or drought-resistance.
To seed your lawn, lay down approximately 1 inch of topsoil, then use a spreader to apply the seed to the soil.
We recommend using two different types of spreaders. For the majority of the work, you should use a broadcast spreader because they distribute seed evenly, allowing for thorough coverage. But you’ll want to use a drop spreader around the edges of garden beds to make sure you don’t inadvertently drop seed into them.
Always set the spreader to half the recommended drop rate and spread the seed in one direction, then one or two more in different directions to make sure the coverage is nice and even. You don’t want your lawn to have weird patterns or stripes.
Applying the right amount of seed is key. As a general rule of thumb, apply roughly 15 seeds per each square inch, then rake over the seed.
Top the seed with top dressing no greater than ¼ inch thick.
Then, it’s time to add starter fertilizer. Your best bet is to use a starter fertilizer high in phosphorus. However, due to concerns about water pollution, many states prohibit the use of phosphorus in fertilizers. Some states may allow phosphorus in fertilizers for establishing new lawns. If so, you’ll find fertilizers labeled “new lawn” or “starter fertilizer.”
Step 9: Water Your Lawn
Deep, infrequent watering can help establish your lawn by allowing it to grow deep roots, which can compete against weeds. Try to water your lawn about twice a week, in the morning before the heat of the day sets in. Lawns typically need about 1.5 inches of water per week, but that could vary based on the climate you live in and the type of grass seed you chose.
Step 10: Maintain Your Lawn
Proper maintenance is critical if you want your newly established lawn to stay weed-free. Mow at either the highest or second-highest setting. Vigorous grass won’t be choked out by weeds. Fertilize your lawn as needed to help it thrive.
3 Reasons Your Lawn Is Full of Weeds
Starting out, you probably want to know just why weeds have overtaken your grass, so you can prevent it from happening again.
- Poor grass growth: Weeds thrive in thinning grass. The best way to keep weeds out is to have thick, tall, dense grass all over your lawn. If your grass is cut too short, it’s more susceptible to a full-on weed invasion. Setting your mower to the highest setting can help with this.
- Not enough water: Weeds tend to have robust root systems, and can easily compete with your grass for moisture. If you are not watering your grass enough, the weeds can absorb what water there is, taking it away from your grassroots.
- Compacted soil: If your soil becomes too compacted, whether from excessive foot traffic or poor soil composition, your grassroots won’t have access to the nutrients, water, or air they need. This stressed turf makes for an exceptional weed breeding ground.
Professional Lawn Care
Once you’ve put in all that hard work, you’ll want to keep up with it. The prospect of regular lawn maintenance can be daunting, from fertilization to aeration to yet more weed control. Hiring a professional lawn care company like TruGreen can alleviate those concerns.
TruGreen offers five different annual plans for your lawn care needs, offering a range of services. Plans come with the TruGreen Healthy Lawn Guarantee®, promising full-program customers that a TruGreen specialist will return to your home as many times necessary to resolve your issues.
Our Rating Methodology
To provide readers with the most objective, accurate, and detailed recommendations, the This Old House Reviews Team continually researches lawn care service companies on the market. We take the following steps to obtain up-to-date information about the industry and each company we review:
- Analyze more than 100 customer reviews from third-party review sites, such as Yelp, the Better Business Bureau (BBB), and Google Reviews, for each company
- Secret-shop for lawn care plans and packages to get a sense of cost, offered services, and the overall shopping experience for prospective customers
- Speak with representatives on the phone to simulate the customer service experience from each provider
- Update information on a regular basis to ensure the most accurate information when plans or services change with each company
We use the data from our research to build an in-depth rating system that allows us to score lawn care providers on a 100-point scale. Here are the factors in our evaluation and their designated scores:
- Plan options (30): As one of the most important factors for homeowners shopping for a lawn care service, this one is weighted heavily based on each company’s lawn coverage. Companies that offer more options, such as irrigation, weed control, seeding, and aeration services in addition to a general plan, score higher than others.
- Trustworthiness (30): Each company’s reputation is another significant factor for homeowners to consider before signing up for a plan. We scored providers based on their BBB score, accreditation, and offered guarantees available with each purchase.
- Additional Benefits (20): We gave extra points to companies that provide a few additional services and benefits with their offered plans, such as organic treatments, pest control services, and a mobile app for digital communication and plan management.
- Customer Service (10): In this rating category, we awarded points to customer-focused lawn care service providers who offer weekend availability and easy communication through phones, online chats, and online resources.
- Availability (10): We also scored companies based on their overall availability, rewarding those that are nationally available over local companies only operating in select cities or ZIP codes.
To share feedback or ask a question about this article, send a note to our Reviews Team at [email protected]iews.com.