To kill weeds and grass in isolated locations, spray herbicides only when the air is calm and cover nearby plants with plastic to protect them from spray drift. Target specific weeds directly by dabbing herbicide onto the leaves of the weed.
Spray drift, also called overspray, occurs when herbicide that was intended only for weeds comes in contact with desired plants. To avoid spray drift and spray in an isolated spot, create a targeted spraying area. Remove the top and bottom of a can or jug, and place it over the weed. This prevents the spray from getting on any other plants.
Another way to kill weeds in an isolated location is to lay plastic over all the plants in the area and cut a hole just above the weed. Pull the weed through the hole in the plastic, and spray it with herbicide. Remove the plastic wrap once the herbicide is dry.