All of my basil plants have downey mildew and I threw out the plants and the soil. They were in a large resin barrel and I want to know what is the best way to sanitize it before I plant more basil in it.
From the reports of commercial growers, it sounds like all you need do is get rid of all plant debris. They either removed & destroyed the infected plants or plowed them down.
Contact your county';s Extension Service office as they should have "real" advice for you.