First off........plants ARE NOT DRUGS. They are plants.
Second, God Himself told Adam and Eve (when He kicked them out of Eden), "if it grows out of the ground, you may have it". He told the same thing to Moses on Sinai.
Marijuana, peyote, mushrooms, and (yes) even opium are all plants. It's only when you refine it to the point that all the plant material (i.e. the "safety valves") are gone, then you would see where it becomes a drug. Cocoa plants are NOT drugs......they're plants. But, when you refine it to the point where all you have left is the active substance, that is the point where it becomes a drug.
Legalize all plants, but DO NOT legalize drugs like meth and heroin.