Well the title will probably throw several people off because it's not cannabis related...but it is organic and weed related...hehe.. I have several clients who are 100% organic and won't allow any synthetic fertilizer or weed killer on their property. These clients either have brick patios or driveways that get attacked by local weeds. I heard that vinegar and water at 50/50 ratio will kill pretty much anything. Any other suggestions? I'm wondering if I should just brew barley for 10 hours and let it turn acidic...throw it in my backpack sprayer and go to town on the driveway and patios....
You want a higher % of acetic acid than what a 50/50 vinegar to water ratio will get you. Look at horticultural vinegar. You also need to spray on the hottest days, full sun (from experience) and since it only kills the leaves, if you have perennial weeds they will just come right back. There is a more awesome option:
An important part of using vinegar to kill plants is the addition of soap (I use dish soap). The soap helps breakdown the waxy surface of the leaves so that the vinegar can do its job.
I really hate those types of customers, though. If you properly mix glyphosate and only spray enough to coat the leaves, have no drift, and especially are spraying on hardscape, you are not contaminating anything.