Does Vinegar Kill Weeds?

Does vinegar kill weeds, or is that just an old wives’ tale? Sometimes, old wives are right because vinegar is a natural weed killer that works. Many weeds die within a day of coming into contact with it.

Vinegar weed killer sprays are the most popular natural herbicides because they are non-toxic, affordable, and easy to apply. But if you want weeds out of sight, you must use vinegar correctly. No worries. We use expert insight to explain everything from choosing the most potent vinegar to properly applying it.

How vinegar kills weeds

Vinegar’s active ingredient, acetic acid, kills weeds by dehydrating them. When acetic acid touches a plant, cell walls shatter, and moisture escapes the plant’s tissue. After a few hours, most plants show a decline. Within a day, many weeds shrivel up and die. 

Vinegar is a non-selective contact herbicide, and one of the best post-emergent herbicides:

• Contact herbicides can’t infiltrate a plant’s root system. Instead, they damage the parts they touch, like the stems and leaves. 

• Non-selective herbicides aren’t picky about which plants they pursue. Joe Neal, professor of weed science and extension specialist at North Carolina State, says, “Any green plant that they contact will be injured or killed.”
• Post-emergent herbicides kill weeds after they sprout. Since vinegar dehydrates existing plants, it’s a type of post-emergent herbicide. Along with renting a goat, it’s one of the best natural weed killers.

My tip: Vinegar doesn’t impact the soil for long. A few days after applying vinegar, new seedlings may sprout. Keep an eye on where you applied vinegar weed killer and reapply it as necessary.

Easiest weeds for vinegar to kill

Although vinegar harms just about any plant, it controls some weed types better than others. It’s most effective at killing young annual broadleaf weeds, and least effective on mature perennial and grassy weeds.

Before applying vinegar weed killer, consider how well it controls the type of weed in your yard:

• Maturity: Since acetic acid kills with contact, it’s most deadly when it touches every leaf on a plant. Thus, vinegar weed killer is especially effective at eradicating young seedlings, and not as good at dealing with overgrown weeds.

• Leaf size: When comparing broadleaf vs. grassy weeds, vinegar is better at killing the former. As the name suggests, broadleaf weeds have bigger leaves, giving acetic acid ample access to the large targets. 

Common broadleaf weeds	Common grassy weeds
Dandelion	Crabgrass
Common plantain	Annual bluegrass
Creeping Charlie	Quackgrass
White clover	Nutsedge
Chickweed	Foxtail
Broadleaf plantain	Barnyard grass
Oxalis/wood sorrel	Goosegrass
Common purslane	Dallisgrass

• Growth cycle: When comparing annual vs. perennial weeds, vinegar is much better at combatting annuals. Since annual weeds don’t grow back from their roots like perennials, they easily succumb to contact herbicides. 

Will vinegar kill grass? Vinegar isn’t healthy for your lawn because it can damage or kill grass. When targeting weeds, I recommend using a spray bottle with a precision nozzle to focus the application directly on unwanted plants while minimizing contact with your lawn.

Best types of vinegar to kill weeds

Unsurprisingly, vinegar is more effective when it contains a higher level of acetic acid. Vinegar containing 5 to 10% acetic acid kills up to 2-week-old plants, says the Purdue University Extension, but an acetic acid concentration of at least 20% kills older weeds. 

Household vinegar

With an acetic acid concentration of 5 to 10%, household vinegar is the weakest at killing weeds. Although it can kill annual broadleaf weeds under 2 weeks old, the University of Maryland Extension says household vinegar can’t control most weeds. On the flip side, it’s one of the safest non-toxic weed killers. 

Horticulture vinegar

With an acetic acid concentration from 20 to 30%, horticultural vinegar is much more effective than household vinegar. After a few applications, it often slays perennial, grassy, and mature weeds. In fact, the U.S. Department of Agriculture says horticultural vinegar kills 85 to 100% of weeds at any growth stage.

However, with great power comes great responsibility. Apply horticultural vinegar with caution to avoid the following hazards:

• It can burn your skin.
• It can irritate your eyes and sometimes cause blindness. 
• If too much touches your turf, the grass will die.
• Wind can carry it to another part of your yard, harming desirable landscaping.
• Wind can carry it to your neighbor’s yard. And if you damage your neighbor’s daffodils, they’ll likely get sad or angry. 

My tip: Some industrial-strength vinegars have as much as 50% acetic acid, but we don’t advise using a product that’s higher than 30%.

Vinegar weed killer recipe

Skill level: Beginner Coverage area: Roughly 300 to 400 sq. ft. for spot treatment Length of project: It only takes a couple of minutes to mix your DIY weed-killer solution. Estimated cost: $20 to $35 with household vinegar or $35 to $55 if you opt for horticultural vinegar.

Our vinegar weed-killer recipe is organic, affordable, and easy to make. Homeowners can quickly create the compound from a couple of common cupboard items. Hence, our natural weed-killer spray is perfect for beginners on a budget. 

What you need:

• 12 cups of vinegar
• 1  tablespoon of dish soap
• Garden sprayer (I recommend the Chapin Home Sprayer.)
• 3/4 cup of salt (optional additive)

Directions:

1. Choose the type of vinegar. Use household vinegar for annual broadleaf weeds under 2 weeks old and horticultural vinegar for anything else.
2. Pour the vinegar into a mixing container or directly into the sprayer. If you’re not using all the solution at once, mix it in a sealable container for storage. 
3. Add the dish soap to the vinegar.
4. Before adding salt, consider the situation. For example, many homeowners add salt if treating a gravel driveway or preparing to build a patio. Only add salt when both a and b are true:
   1. You want to kill every plant within the solution’s reach, accounting for wind.
   2. You don’t want to grow anything in the soil for at least 6 months. 
5. Mix the ingredients evenly to create a uniform solution.   
6. Apply with a garden sprayer. 

Benefits of adding dish soap to vinegar weed killer

The dish soap is a surfactant, helping vinegar and salt stick to slick leaves. Although it’s not overly harmful alone, it assists in dehydrating plants. When sizzling in the summer sun, sometimes soap even burns leaves.

Benefits of adding salt to vinegar weed killer

Salt amplifies vinegar’s ability to dehydrate plants. Then, after seeping deep into the soil, it damages plant roots and degrades the soil. Thus, table salt has the following hazards:

• Damaging nearby grass and landscaping
• Killing the microbes that organically fertilize the soil
• Possibly, increasing the soil’s pH level

With that said, some salt-tolerant species aren’t bothered by table salt. Epsom salt works better on these plants, and it doesn’t degrade the soil. Unfortunately, since Epsom salt is rich in micronutrients, it also fertilizes some weeds. 

Tips for using vinegar to kill weeds

To get the most out of vinegar weed killers, follow these tips:

• Timing: The early bird catches the worm, so apply vinegar weed killer as soon as you see weeds sprout.
• Weather: The brighter the sun shines, the faster the weed dies. Vinegar works best on hot, dry days with full sun. It’s best to avoid applying vinegar when it’s raining or windy. Rain dilutes the vinegar, and wind can blow it on beloved plants.
• Coverage: Saturate all the weed leaves without spraying any desirable vegetation. 
• Spot-treating turf: Carefully apply spot treatments with a paintbrush, making sure the vinegar doesn’t touch any grass blades. Additionally, we recommend that you only use household vinegar on lawn weeds.
• Safety: To avoid contact with skin and eyes, wear gloves, long sleeves, pants, closed shoes, and safety goggles. Keep horticultural vinegar safely stored away from children and pets, and never put it in your mouth.

FAQ about vinegar weed killer

When to call a weed control pro

The best way to rid your lawn of weeds is to contact a weed control pro. Lawn Love links you to qualified pros who control weeds and fertilize grass. We also help homeowners with routine lawn mowing.

It only takes a moment to get an online quote and gain access to our network of pros. Before joining our community, pros must pass a background check, show proof of insurance, and earn excellent customer feedback. 

Main Image Credit: Daria Nipot | Adobe Stock