Is it safe to use horticultural vinegar on graveled drives?
Question:
How safe is it to use horticultural vinegar on graveled drives? Is it safe to use it close to a well?
Answer:
“Safe” is always a relative term when using chemical interventions in the garden–horticultural vinegar is a 20% solution of acetic acid (4x stronger than household vinegar), which can be every bit as dangerous as a synthetic herbicide under the right circumstances. I say this to combat any notions that “natural” or “non-toxic” herbicides aren’t actually chemical pesticides (they are, by legal definition), and to stress the importance of always reading carefully and following conscientiously all instructions on the label.
That said, if you are using horticultural vinegar properly on weeds on a gravel driveway, you should be just fine and avoid any long-term problems to your own health or desirable plants nearby. Please not that the vinegar only works as a direct contact herbicide (it only damages plant tissue it touches at full strength) and is primarily effective against young annual weeds. Because the vinegar dilutes in soil and water, it doesn’t do much against perennial or well-established larger weeds (though it will still kill any aboveground tissue on those plants), so you’re looking for a targeted approach on vulnerable weeds, not a broad or indiscriminate application.
You will definitely want to wear protective gear (e.g., rubber gloves, eye protection, etc.) when applying it and avoid ingestion, inhalation, and contact with skin or eyes.
I don’t anticipate any problems for your well if the vinegar is used appropriately and in small amounts.
Happy gardening.