You want a beautiful, weed-free garden, but you probably also want a product that can kill weeds without harming your children and pets. Red cider vinegar can kill many common weeds and is safe to use outdoors where kids and pets roam. But you do have to be careful when using vinegar as a herbicide, because it does not discriminate when it comes to killing plants -- it kills both weeds and desirable plants.
How It Works
Red cider vinegar -- like most vinegars in the kitchen -- contains about 5 percent acetic acid and 95 percent water. When this acid comes into contact with weeds, it dries them out. Red cider vinegar only kills the plant parts in comes into contact with, so it does not kill plant roots. Five percent acetic acid is a low concentration, and red cider vinegar works best on small, young weeds, rather than older, established and stubborn weeds.
How to Apply
Pour the red cider vinegar into a spray bottle if you want to use it on weeds near flowers or vegetables. Because it kills any plant it comes into contact with, be careful it only comes into contact with weeds. Use the spray bottle on calm days with no wind. Shield nearby plants with a piece of plastic or cardboard, if you're worried about hitting them with the spray. Red cider vinegar works more effectively when you spritz weeds on warm, sunny days, because sunlight activates the vinegar. Several applications may be necessary for stubborn weeds.
When to Apply
Red cider vinegar works most effectively when sprayed on weeds before they set seed. So, it is best to spray weeds in spring, before they mature. Red cider vinegar is more effective on perennials weeds when used in the fall. Using the vinegar in fall takes advantage of the weed's natural growth cycle and allows it to absorb the vinegar to the roots where it can kill the entire plant.
If you are worried about red cider vinegar getting on desirable plants while spritzing, do not use it. Instead, use an old paintbrush, dip in the vinegar and brush it generously on weeds. Vinegar is an acid, but it breaks down rapidly in the soil, so there is little risk of adverse effects on flowers and vegetables. The acid only remains in the soil for a few days, so it does not permanently affect the soil pH level. Red cider vinegar will have the same effect as the less expensive white vinegar, so don't go out of your way to use red cider vinegar.