Let me deal with a few garden myths right off the top about controlling weeds with vinegar.
Household vinegar doesn’t work.
Household vinegar doesn’t work. Period.
I don’t care what the Internet says. In my trials all it’s good for is seasoning the dandelion leaves to make them taste better for the slugs.
What Vinegar Does Kill Weeds?
- Pickling vinegar at 7% acetic acid will burn “some” leaves and won’t burn others. But it has to be a full, heavy spray totally covering the leaf.
- Cleaning vinegar at 10% acetic acid will burn most leaves
A vinegar weed kill recipe I use:
- I use a gallon of cleaning vinegar (10% acetic acid)
- 1-2 tablespoons of cheap vegetable cooking oil.
- dash of liquid soap as a spreader.(essential)
I gently heat the vinegar until it dissolves the salt, mix it up with the liquid soap and then use it right way.
In repeated trials, this burns most common weeds it touches *if* you totally cover the leaves.
Some leaves (for example, sumac and aegopodium) burn in spots and are distinctly unhappy. Others (dandelion will burn completely with full coverage)
Your burn effectiveness will depend on your coverage and the plant being sprayed (there’s no one size fits all here).
This is a “burn” type of spray so while you burn the tops off, the roots are quite happy underground and will resprout quickly. If you don’t respray, (see below) then you’re wasting your time. You have to continually burn the new leaves as they emerge.
I Sprayed Some Aegopodium
This plant (goutweed) is a noxious spreading weed and imho, should never be allowed into a garden.
It took me 6 sprays (7-10 days apart) to mostly kill a section of aegopodium with the 7%. It turned the ground so acidic, we had moss growing there in the spring. And the surviving Aegopodium came up through it.
It burns what it touches and that includes good stuff and bad stuff. As indicated, repeated sprayings every 7-10 days are needed for perennial plants and even then the results are mixed.
It would have been better and less work to have simply dug up the patch (certainly cheaper)
Three years of multiple sprays and Potentilla pleniflora (royal cinquefoil) is still hiding and emerging. I am beginning to seriously dislike this plant.
Cleaning Vinegar at 10% acetic acid works better. It can often be found in the “cleaning” section of big grocery stores
20% Acetic Acid I now purchase larger quantities of 20% acetic acid for serious burning.
That’s the bottom line on whether vinegar works as a weed killer. It might, but it depends on the concentration of acetic acid and the plant you’re trying to kill.
But don’t believe the Internet on this one.
You can see other practical landscaping tips here