Using something as potent as Roundup in your garden can be a nerve-wracking experience, right?
Is it going to work? Will it kill what you want it to? Is it going to harm anything else?
And a common question, particularly when it comes to using weed killers on lawns, is will grass grow back after Roundup?
Read on to find out, complete with essential tips and advice on how to save and regrow a damaged lawn if necessary.
- Will Grass Grow Back After Weed Killer? Too Long, Didn’t Read
- What is Roundup?
- Selective and Non-Selective Herbicides
- Roundup and Grass – What You Need to Know
- How to Remove Dead Grass After Roundup
- How to Regrow Grass After Roundup
- Final Thoughts
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Will Grass Grow Back After Weed Killer? Too Long, Didn’t Read
If you’re panicking because you think you’ve just sprayed a potent chemical where you shouldn’t, then here’s the answer up front:
It depends on the type of weed killer used, how much the grass has been exposed to, and the climate conditions, when it comes to whether the plant will bounce back or not.
But as a general rule of thumb, if you’ve not seen an improvement in your lawn or “dead grass” area after two weeks, then you can probably bet it’s not going to come back anytime soon.
If that’s the case, we’ve got some top tips coming up on how to return your lawn to its former glory, so you can stop hitting your head off a brick wall.
What is Roundup?
Roundup is the brand name of one of the most popular vegetation control products on the market, manufactured by Monsanto, which in turn was acquired by Bayer Pharmaceuticals in 2018.
Its most (infamous) ingredient is glyphosate, which is never too far away from the news, given that there’s evidence it is carcinogenic to us humans (when used in large quantities/incorrectly).
It’s a systemic, broad-spectrum herbicide, which basically means it attacks the system of a wide variety of plant life.
And it’s very potent at what it does.
Take a look at this article if you are looking for the best weed killers for driveways.
Top tip: There are many other branded weed killers that also use glyphosate as their active ingredient – not just Roundup. You should always make sure you know exactly what you’re spraying beforehand.
While this article uses the Roundup brand name, the same advice can be more or less said when using other glyphosate-based herbicides, or non-selective herbicide use on the lawn in general.
Selective and Non-Selective Herbicides
Without going into too much detail here, weed killers like Roundup are available in two distinct types – selective and non-selective herbicides.
Selective herbicides will only attack specific weeds – usually as noted on the product’s packaging or specifications.
Non-selective herbicides will damage or destroy pretty much any vegetation they touch – including desirable plant life, such as vegetables, flower beds, and – of course – grass.
(Check out this review of the best commercial-grade weed killers – most of which will be of the potent, non-selective variety.)
Why is this information important?
If you’ve sprayed a selective herbicide on your lawn – that has been specifically designed to tackle lawn weeds and leave the grass alone – then you shouldn’t have anything to worry about.
And Roundup manufactures a product that does just that – Roundup for Lawns. If using this particular weed killer, then grass will grow back, because it hasn’t been damaged in the first place.
However, if you’ve made a glaring error and accidentally sprayed a non-selective herbicide on your lawn, (such as the vast majority of Roundup’s other products), then you should keep reading to find out how to deal with it.
For more specific help, this article on the best weed killers for flower beds will advise you on what to lay down around desirable plants.
And this piece on pre-emergent herbicides is ideal if you need help preventing a weed problem before it’s begun.
Roundup and Grass – What You Need to Know
So, you’ve either chosen the wrong herbicide, or you’ve accidentally sprayed in the wrong place, or maybe you’ve been applying the weed killer during windy weather, and it’s dispersed from its intended location.
Either way, you suspect your lawn has taken a dose of a non-selective herbicide, and you’re panicking that you’ve killed it off.
Your immediate response should be to douse the area with a liberal spray from the hose – as watering the Roundup down will help to reduce its potency, and give your grass a better chance of recovery.
If, however, you were unaware that the herbicide has traveled, your lawn might only start to show signs of “burning,” several hours, or a few days after application.
Yellowing, brown, discolored grass patches begin to appear – a tell-tale sign of herbicide damage.
Why is this happening? It’s time for a brief lesson from grade nine biology.
Non-selective herbicides, such as glyphosate, work by inhibiting a plant’s ability to use photosynthesis – the process in which they use sunlight to help create food from carbon dioxide and water.
Take this ability away, and the plant will start to die.
The green pigment in a plant – chlorophyll – begins to turn color, which is unsightly and often concerning appearance we’re greeted with when looking at grass that has been damaged by chemicals.
But the key question is – is this damage permanent?
It depends on how extensive it is, how much weed killer has been absorbed, how hot the climate is, and how long the plant has been exposed to the herbicide.
There’s nothing much more you can do at this point but to watch and wait.
The grass could well bounce back in a few days – that attractive green hue will start to return, and the crisis is averted.
But if you still have brown or yellow patches on your lawn for 14 days after application, then it’s going to be bad news, I’m afraid. There’s a strong chance the grass has been killed to the root and is gone for good.
In which case, you should read on to discover the next steps for lawn recovery.
How to Remove Dead Grass After Roundup
The worst-case scenario has occurred, and you have no chance of salvaging sections of your lawn. The deed is done, the grass is dead.
Long live the grass.
The good news is that all is not lost. Follow the steps below, and with a bit of hard work and the right conditions, a thriving, green, healthy lawn will soon return.
First, the dead material needs to be removed in order to establish a blank canvas. There are several ways in which to do this, and the type you choose will depend on the extent of the damage.
You might be able to use some good, old-fashioned elbow grease, get down on your knees and use your hands to strip the layers of dead vegetation away.
For tougher, more extensive spots, a dethatching rake should be implemented. Just be careful not to hack away at any desired, living material.
This article on the best dethatchers should help get you started.
And this article might offer additional help if you’ve discovered some unsightly yellow patches on your lawn.
But if your lawn is a total write-off, and/or the area is simply too large to do by hand, then you might want to look into using a sod cutter to lift the dead material away and start totally from scratch.
Either way, before attempting to regrow areas of dead grass, you should be down to the bare soil before a single seed is sown.
How to Regrow Grass After Roundup
Once the dead grass has been removed, and you’ve exposed the soil, you’re ready to start reestablishing your lawn.
This is where the hard work really begins.
But you actually don’t want to rush in – especially after the damage has been done by initially spraying herbicides.
How long you wait before applying grass seed will depend on the chemical that’s been applied in the first place. Check with the particular product you’ve used.
For the most part, you’re looking at a minimum of three days before new seeds can be applied.
Next, (if you have any lawn left) you should mow the grass down to the lowest setting on your lawnmower. This article on the different types of lawnmowers will help make sure you’re using the right one.
Then, simply follow the advice in the video below, which offers a great visual guide on how to regrow areas of your lawn that have died.
But perhaps one of the most important steps when it comes to growing a healthy lawn, is how best to water it. Too much is just as bad as too little, which is particularly critical when it comes to new growth.
This in-depth article on how to water your lawn should tell you everything you need to know.
Here at Yardthyme we always try to promote organic ways to care for your lawn and garden. This article on how to get rid of dandelions naturally is a good example.
This piece on pet-safe weed killers is another.
But we recognize that sometimes a powerful chemical herbicide is the only thing that will do.
That said, always take the greatest of care when choosing this course of action, and only as a last resort if you can help it.
Unfortunately, such potent herbicides are often a necessary evil for achieving the landscape of our dreams. In the end, Mother Nature always wins.
Is Roundup safe to use?
Yes and no. It’s a bone of contention in the agricultural community, as there is maybe some evidence to suggest it’s harmful if used in large quantities, and it’s certainly harmful if used improperly.
And there’s no denying it’s not safe for the plants it’s used on.
For residential use, caution is advised – particularly when spraying near desirables, in windy or rainy conditions, and/or if you have children/pets.
If you are genuinely concerned about its usage, you can take a look at this article on the best alternatives to Roundup.
However, at the time of writing, the US Environmental Protection Agency has found no evidence that there is any detriment to human health from the use of glyphosate.
And Bayer, the pharmaceutical company that manufactures this particular brand, has stated that they will be offering weed killer products under the Roundup name that contain alternative ingredients.
How long will Roundup stay in the soil?
Roundup can stay in the soil anywhere from three days to over a year – it just depends on the type of product you’ve used, and how much has been applied.
It can also depend upon the climate and type of soil it’s in.
When in doubt, check directly with the manufacturer of the specific glyphosate-based product you’ve used.
How long after spraying Roundup can you sow grass seed?
Depending on the type of Roundup, it is recommended that you wait a minimum of three days before attempting to sow any new grass seed.
Will Roundup kill Bermuda grass?
Provided you’re using a non-selective version of Roundup, then there’s a strong chance it will kill Bermuda grass.
However, as this plant can be a particular nuisance when it’s not wanted, it’s highly recommended that you take a look at something that specifically targets the golf-course favorite grass.
Can check out this review of the best weed killers for Bermuda grass on the market.
Will grass grow back after Roundup? It depends on a number of factors, but so long as the plant hasn’t been exposed to too much of the chemical, and it’s given a chance to return, then you might get lucky.
Follow the advice and the steps above, and you won’t go too far wrong. Remember – it might look bleak, but with the right conditions, nature will find a way.
Let me know your lawn and herbicide experience in the comments, stay safe out there, and happy gardening!