The natural way to control weeds is to build the soil by increasing the organic matter and most weeds won’t be a problem. In the interim, hand pull problem weeds, spot spray with vinegar-based herbicides and apply corn gluten meal at 20 lbs./1,000 sq. feet spring and fall prior to seed germination.
For winter weeds, spray between Christmas and New Years with vinegar. The best mixture is full strength 10% pickling vinegar into which is mixed 2 oz. orange oil and 1 teaspoon liquid soap per gallon of vinegar. This technique works fairly well any time during the winter when the summer grasses are dormant.
A quality commercial product is Avenger Weed Killer.
Weeds in Paved Areas
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 like Avenger Weed Killer.
Weeds in Beds
Weeds in beds can be killed by removing the tops and then covering the problem area with 1/2" of compost followed about 5 layers of newspaper. Wet it all down and cover the paper with 2-4" of shredded mulch. Spot spray any weeds that manage to come through with the vinegar herbicide or commercial organic herbicides.
Vinegar Herbicide Formula:
1 gallon of 10% vinegar
Add 1 ounce orange oil or d-limonene
1 teaspoon liquid soap or other surfactant (Bio Wash)
Add molasses at 1 tablespoon per gallon to the vinegar formula
Do not add water