Vinegar and orange oil have become staple products in the organic program and easier to find in garden centers, hardware stores and feed stores.
Vinegar is a wonderful organic tool that was discovered by accident ten thousand years ago when wine was accidentally allowed to ferment too long and turned sour. It can be made from many products, including beer, apples, berries, beets, corn, fruits, grains, honey, malt, maple syrup, melons, molasses, potatoes, rice, sorghum, and other foods containing sugar. Natural sugars from these food products are fermented into alcohol, which is them fermented into vinegar.
The strongest vinegar available in retail stores is 30% but it is far too strong and I do not recommend it. For general use, 20 percent or 200 grain is available but it is stronger than needed. At this strength it is corrosive enough to eat metal and must be handled carefully in plastic containers. It is also dangerous to breathe. It works best when sprayed full strength during the heat of the day and in full sunlight. While 200-grain (20 percent) material is still on the market, it can be reduced to the recommended 100 grain (10 percent) by adding water in the 20% vinegar. Diluting cuts the cost in half and makes it a safer product to use. The mix I recommend for weed non-selective weed control is 1-2 oz. of orange oil and 1 teaspoon of liquid soap per gallon of 10% (pickling) vinegar made from grain alcohol. Vinegar that is made from the petroleum derivative, 99% acetic acid, is not acceptable in an organic program.
If your water is alkaline, add 1 tablespoon of 50-grain (5 percent) natural apple cider vinegar to each gallon of water to improve the quality of the water for potted plants and bedding. This doesn’t have to be done with every watering, though it wouldn’t hurt. This technique is especially helpful when trying to grow acid-loving plants such as gardenias, azaleas, and dogwoods. A tablespoon of vinegar per gallon added to the sprayer when foliar feeding lawns, shrubs, flowers, and trees is also highly beneficial, especially where soil or water is alkaline. The other horticultural use for vinegar is the watering can.
Fruit vinegar is made from the fermentation of a variety of fruits. Apples are most commonly used, but grapes, peaches, berries and other fruits also work. The product label will identify the starting ingredients, such as “apple cider vinegar” or “wine vinegar”. Malt vinegar is made from the fermentation of barley malt or other cereal grains. Sugar vinegar is made from sugar, syrup, or molasses. White, spirit, or distilled vinegar is made by fermenting distilled alcohol. Distilled white vinegar is made from 190 proof alcohol that is fermented by adding sugar and living bacterial. Natural vinegar contains at least fifty trace minerals. Vinegar that is made from the petroleum derivative, 99% acetic acid, is not acceptable in an organic program.
Treat Weeds in Paved Areas with Vinegar
Weeds can be controlled with non-toxic products. Forget using black plastic, toxic chemical herbicides, salt and bleach. Remember one of our primary rules – do nothing to harm the life in the soil. Bleach and toxic chemical herbicides are poor choices, but there are some good ones.
To keep the weeds out of a decorative or utility gravel area, the best approach is to design them out from the beginning or use organic products later to kill the weeds. Salt, toxic herbicides and bleach should never be used because they contaminate the soil long term. They also leach into the water stream. To head off the problem, install the gravel in a thick layer – 6-8” after scraping away all grasses and weeds.
For additional control, add a layer of white caliche rock before putting the gravel on top. Any weeds that grow through the gravel can be sprayed and killed with a mix of 10% pickling vinegar mixed with 2 ounces orange oil and 1 teaspoon liquid soap or you can use commercial organic herbicides. There are also commercial products now available. Vinegar sprays can also be used to kill weeds in the cracks in sidewalks and driveways.
Note from a listener: ALWAYS add high-percentage acetic acid (or any strong acid) to water to prevent the possibility of dangerous spattering, NEVER the reverse. Likely a good idea to wear eye protection as well. This was stressed frequently in organic chemistry lab when I was in college. --Terri B