Can This Popular Vinegar Mixture Really Keep Weeds Out of Patio Cracks?

Every yard and garden has weeds, and we’re all looking for easy and effective (even magical!) ways to kill those weeds and keep them from returning. Weeds are especially troublesome when they grow between cracks in driveways, patios and sidewalks.

The internet has a proposed solution: Grab a jug of vinegar from under your kitchen sink, mix it with a little dish soap and salt, put it in a spray bottle and spritz away.

But is vinegar actually the easy, effective, magical answer for weed control everyone is looking for?

Does Vinegar Really Kill Weeds?

You’ll find numerous recipes online for DIYing a natural vinegar-based weed killer. Most list white vinegar (five percent acetic acid), salt and dish soap as the main ingredients. After mixing them together, spray the solution on your weeds on a bright, sunny day when the foliage is dry. Then stand back and watch those weeds quickly turn brown.

Problem solved?

No. The household vinegar most of us have on hand is too weak to kill weeds, even if applied over and over. Combined with salt, it may turn the weeds brown, but their roots will still be alive. Within a few days, those weeds will grow back.

Can You Use Stronger Vinegar To Kill Weeds?

There are stronger vinegar based weed killers out there. Many contain 20 percent acetic acid, which is really strong.

According to Denise Schreiber, a certified pesticide applicator and the author of Eat Your Roses, “There are horticultural vinegars that are 20 percent acetic acid and higher. These require eye protection in case of an accident. They will kill grasses in cracks and a few other annual weeds.”

Schreiber also notes these vinegar-based herbicides don’t kill perennial weeds, which are often the weeds that most of us have problems with. That’s because vinegar is a contact herbicide that only kills the foliage it touches, not the roots. So again, that weed will soon grow new foliage.

Potential Problems With Using Vinegar as a Weed Killer

There are several potential problems with using vinegar as a weed killer.

• A vinegar strong enough to kill weed foliage can also burn your skin and cause blindness if it gets in your eyes. You must wear wrap-around safety glasses and cover your skin completely to avoid getting the vinegar on you. Be as careful with vinegar as you would be with any dangerous chemical and always follow the instructions on the label. (Note: If you purchase horticultural vinegar that isn’t labeled as a weed killer, it’s illegal to use it as a weed killer.)
• Vinegar isn’t selective. It will kill the foliage of any plant you spray it on. If you use vinegar or any weed killer around plants you don’t want to harm, shield them in some way. And never spray any weed killer on a windy day.
• Strong vinegar may discolor or damage some types of patio material.

How To Get Rid of Weeds in Patio Cracks

I remove weeds in the cracks of my patio two ways. Neither involves vinegar.

• I pull them out by hand. They usually come out easily after a good, soaking rain. For stubborn weeds in pavement cracks and between pavers, I dig them out with a patio knife.
• I carefully use a string trimmer to cut off the weeds if they’ve gotten out of control (which happens sometimes). I always wear long pants and eye protection when doing this.