5/12/2023 - We still get many hits on this post, so be sure to check the updates at the end.
8/13/2013 - I was having a discussion with a colleague about organic agriculture the other day and the subject of weed control came up. Here is western North Carolina weed control is one of the major challenges in an organic system. He made the comment that there are no effective organic herbicides. I have tested a number of commercial organic herbicides and wasn't too impressed. The biggest problem I had with those herbicides was that for them to be effective they needed to be applied when the weeds were very small. I invariably missed that narrow window of weed size for effective control.
But in the past two years I've been reading about and hearing from growers about the effective use of vinegar for weed control. I remember trying household (5% acetic acid) vinegar years ago and not being impressed, but higher concentration products are now available. But do they really work? Is there research to back it up? I quick search of the literature (internet) showed that they can indeed be effective.
The study that I think demonstrated this very clearly and simply is this one from Cornell Extension:
Evaluation of acetic acid based herbicides for use in broad-spectrum turfgrass and weed control
Another from Cornell University
Vinegar for Weed Control in Bell Pepper and Broccoli
And one by researchers in Egypt and Florida
Natural Herbicides
Update 2018: I was pleased to learn that people are still reading this article! Unfortunately, I found out about it when a NC extension agent contacted me to let me know that none of the links above worked anymore. So, I found those articles and updated the URLs. Hopefully they will work for a while. I have also found one more article that may be of interest:
A Cornell study that shows more concentrated vinegar is not necessarily better:
2020 Additions:
A US article that shows little benefit to adding oils to acetic acid for weed control:
Impact of Acetic Acid Concentration, Application Volume, and Adjuvants on Weed Control Efficacy
A very positive article about using acetic acid as an herbicide from Egypt:
Authored by Jeanine Davis, NC Alternative Crops & Organics Program, Department of Horticultural Science, NC State University.
