Vinegar - The Organic Herbicide
The best choice for herbicide use is 10% white vinegar made from grain alcohol. It should be used full strength. I've mentioned 20% in the past but it is stronger than needed and too expensive. Avoid products that are made from 99% glacial acetic acid. This material is a petroleum derivative. Natural vinegars such those made from fermenting apples have little herbicidal value. They are used in irrigation water and as an ingredient in Garrett Juice.
1 gallon of 10% (100 grain) vinegar
Add 1 ounce orange oil or d-limonene
Add 1 tablespoon molasses (optional - some say it doesn't help)
1 teaspoon liquid soap or other surfactant (I use Bio Wash)
Do not add water
Shake well before each spraying and spot spray weeds. Keep the spray off desirable plants. This spray will injure any plants it touches. This natural spray works best on warm to hot days.
Vinegar sprayed the bases of trees and other woody plants will not hurt the plant at all. This technique was first learned about by spraying the suckers and weeds growing around the bases of grapevines. Avoid all vinegar products made from glacial acetic acid.