Yes, using vinegar weed killer can help control weeds, which can be a win-win if you're looking for products that are less harsh on the environment than many synthetic herbicides. However, you wouldn't want to use this acidic liquid in all areas of your landscape because it could damage any plant it touches.
The Dangers of Using Vinegar in Your Garden
Vinegar is a contact or "burndown" herbicide, killing what it touches within hours or days. The worst part is that it may looks like it's working, but weeds will then resprout from the roots, particularly perennial species.
Vinegar is acidic and will eventually kill most broadleaf weeds, but the acid will kill the leaves before reaching the root system, and the weeds may grow back quickly. For longer-lasting removal, mix 1 cup of table salt with 1 gallon of vinegar. Salt dries out the weed's root system.
Combine four parts vinegar to one part water. Add about an ounce of dish soap to a gallon of the mixture. Mix well in a spray bottle or other container (if you are not spraying the mix).
Combine distilled white vinegar, salt, and liquid dish soap in your garden sprayer or a spray bottle. Use horticultural vinegar for additional strength. Spray the leaves and stems of the weeds with your solution on a calm sunny day. Reapply the vinegar solution every 2–3 days until the weeds die out.
While vinegar solutions may kill the top growth within a few hours, it might take days for the roots to die off. Boiling water is an effective way to kill weed roots. Try using a tea kettle to help direct the boiling water to the roots.
Glyphosate, the ingredient in Roundup and other products, is translocated from the leaves to the roots of a weed. Vinegar is not translocated. It is true that 5% vinegar (acetic acid) will kill young, tender weeds but it does little damage to established weeds.
“Vinegar is a good cleaner because it's acidic, but when you add dishwashing liquid/dish soap to it (which is a base or neutral) - you neutralise the vinegar. You take away the very thing that makes it work well. “The dishwashing liquid works that well on its own. Adding the vinegar is a pointless step.”
Vinegar with a higher concentration of acetic acid tends to control weeds more effectively. Household vinegar is generally 5% acetic acid. Some herbicidal vinegar products are 20% or 30% acetic acid. In general, 20% or 30% acetic acid is more effective because it more completely kills young leaves and growing points.
Household vinegar often works well on the weeds between the cracks in a sidewalk—the heat from the pavement helps the process along. It's less effective with the perennial weeds that grow in a flower bed. It helps to apply the vinegar every two or three days until the weeds die off.
White vinegar with an acetic acid content of at least 5% will be required to kill most weeds effectively. Apple cider vinegar with the same acid content will also work, though, for tough perennial weeds, you may need a specialised horticultural vinegar with 20% acetic acid.
Rock salt is actually a super-effective and totally natural weed killer that is ace at clearing a gravel driveway. Simply sprinkle some rock salt on the ground surrounding any weeds you can see and then sit back and watch as the salt kills the weeds in just a matter of days. It's almost unbelievable.
What natural weed-killers kill weeds down to the roots? Boiling water and flaming will kill the roots of weeds. Vinegar kills roots, but it may take a few days for the roots to die off after the vinegar solution is applied.
Even though vinegar is an acid, it breaks down quickly in the soil and, therefore, is not likely to accumulate enough to affect soil pH for more than a few days.
This match made in heaven has been a household staple for a long time and I make sure to keep it handy. To make the solution is simple and easy on the wallet! Pour equal parts of vinegar and Dawn into a spray bottle. Gently shake, then spray liberally onto the surface to be cleaned.
5-percent household white vinegar is fine. It may take two or three days longer to kill the weeds with the lower concentration, but it does work. Add 1 cup of table salt. Stir the solution with a long-handled spoon until all the salt dissolves completely.
Also, for best results, try spraying vinegar on a warm, sunny day. Rain can reduce the effectiveness of the weed killer, and strong winds can carry the vinegar and harm desired plants.
Tenacity herbicide is an industry favorite for killing weeds in your lawn without killing your grass. Optimized for cool-season turf, Tenacity can be used as a pre and post-emergent herbicide control for over 46 broadleaf weed and grass species.
To kill weeds, some amateur gardeners recommend combining Epsom salt and Dawn dish soap. Together, these household items create a potent mixture, so only use it in places you wish to eliminate weeds, such as a patio or sidewalk permanently.
Acetic acid is a terrific weed killer but it is also a terrific plant killer! Acetic acid works by drawing all of the moisture out of the weed or plant leaf. It is quick to work and it would be common to see a weed or plant brown up after only a few hours of having vinegar applied to its leaves in the full sun.