Vinegar Weed and Grass Killer

Looking for an effective weed and grass killer that isn’t Roundup, glyphosate, or other chemical herbicides? Look no further than vinegar! Using a vinegar weed and grass killer is a great alternative, and it works very well. See the proof in this post. Affiliate links below; read more about those here.

Vinegar weed and grass killer…yes, it definitely works!

We are deep into yard work season over here, and I wanted to share a quick post on one of the delicious-smelling things I’m using to kill off weeds and grass: vinegar! Yes, I love the smell of vinegar. Reminds me of potato chips and fries.

And what’s better than having your entire yard smell like potato chips? Because, heads up—that’s exactly what happens when you spray your weeds with vinegar. Especially if you’re trying to kill off patches of grass for sheet mulching as we are.

Want more garden content? Check out my My GreenStalk Vertical Planter Review, my post about How to Grow Beautiful Zinnia Flowers, and my Seed Starting 101 post!

Why is vinegar a good choice?

So let’s talk about vinegar weed and grass killer. How does it work? Well, vinegar is made by fermenting ethanol—which is a type of alcohol. During the fermentation process, bacteria convert the ethanol into acetic acid. While most commonly kept in kitchens for cooking, many also use it for cleaning.

It’s effective for cleaning because it is an acid. The acid can dissolve and remove dirt, grime, and mineral buildup from a variety of surfaces. It also has some antimicrobial properties.

It kind of drives me nuts when people say that vinegar weed and grass killer is a good alternative to “chemical herbicides.” Because acetic acid is a chemical. And acetic acid is what makes vinegar, well, vinegar. It’s just acetic acid diluted in water.

When people say vinegar is a good alternative to chemical herbicides, they are often referring to Roundup and similar herbicides that use glyphosate as the active ingredient. I don’t want to get too much into that topic because it’s one of fierce debate given ongoing concerns about its potential health and environmental effects.

In 2015, the World Health Organization classified glyphosate as “probably carcinogenic to humans” based on limited evidence of cancer in humans and sufficient evidence of cancer in laboratory animals. However, other regulatory agencies, such as the EPA and the European Food Safety Authority, have concluded that glyphosate is unlikely to cause cancer in humans.

Environmental impact is also a huge concern of mine. Some studies have suggested that glyphosate may be toxic to these bees, butterflies, and some other aquatic life. Do I know the answer to this? No. But if vinegar works, I’m going to choose vinegar over glyphosate every day.

Can I use regular household vinegar to kill weeds and grass?

You can. There are many recipes online that have you mix regular vinegar with things like epsom salt and dish soap. However, I find that the easiest approach is to use an industrial strength vinegar—also known as horticultural vinegar.

Industrial strength vinegar is simply a highly concentrated form of vinegar. Unlike regular household vinegar, which typically contains 5-7% acetic acid, industrial strength vinegar can contain up to 20-30% acetic acid.

The higher concentration of acetic acid in industrial strength vinegar makes it much more acidic and corrosive than regular vinegar, which can make it effective at killing weeds and other unwanted plants. However—and this is super important—it is also more dangerous to handle.

Wear protective apparel such as gloves, clothing, eyewear, and even a mask when applying industrial strength vinegar. Follow all of the instructions on the container. You do not want this stuff coming into contact with your skin as it is highly corrosive.

How to use a vinegar to kill weeds

So let’s run through how to use vinegar to nuke weeds and grass. For weeds, I use a highly targeted spray attachment to ensure I am minimizing my chances of getting vinegar on plants I don’t want to kill. It will kill plants (my husband accidentally killed a clematis last year).

Suit up with all of your protective gear based on the acidity level you’re using and the instructions on the bottle. Then spray the foliage of the weeds you’d like to kill directly. Try to do it on a sunny day…the sunlight really helps to fry those little buggers!

After a day or so, you’ll notice that the weeds are beginning to die off. After 2-3 days, they should be completely dead. I usually spot treat all of the nasty weeds in my garden and then wait a few days to lay down large swaths of cardboard and mulch.

Then, periodically throughout the summer, I’ll spray particularly nasty weeds that I haven’t been able to control manually. (By manually, I mean pulling them out.)

How to use vinegar to kill grass

We are on a mission to get rid of as much grass as we can in our yard. And that involves a lot of sheet mulching! We don’t till areas where we want to plant or put in mulch beds. Instead, we sheet mulch a lot of it by layering cardboard over the grass and then mulching that.

This takes a bit more time than digging beds out, but it’s highly effective. And you don’t have to find a spot for all of the dirt you dug up like we did last year. Sheet mulching itself can also be an effective method of weed control.

I like to couple sheet mulching with vinegar to jumpstart things. I use industrial strength vinegar for this. But since I am not doing sprays highly targeted to weeds, I like to dilute it a bit with water so it goes farther.

I just kind of eyeball this and add water to a bottle we’ve been using for a while. Then I spray down the area we want to sheet mulch over. It’s also best to do this right after you’ve cut the grass so you have less of a dead mess to cover up.

Again, a sunny day is best. After a few days, it will have gradually started to die off. Layer up that cardboard and mulch to give your grass the ultimate death wish. Works like a charm!

Can using vinegar as a weed killer raise soil acidity?

One thing to keep in mind is that using vinegar as a weed killer can potentially raise the acidity of the soil. This can be great for acid-loving plants like blueberries, but it can have a negative impact on plants that prefer a less acidic soil.

To minimize the risk of soil acidity, you can dilute the vinegar with water before using it as a weed killer. And apply it only to the leaves of the targeted weeds. Don’t saturate the soil with it. And I do it only 2-3 times a year—a big spray of all weeds in the spring, and then highly targeted sprays to keep weeds under control over the summer.

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