Botanical medicine, the art, and science of collecting, preparing, and utilizing plants for healing, is one of the oldest healing methods in human history. The World Health Organization estimates that 80 percent of the world’s population presently uses herbal medicine for some aspect of primary healthcare.

There is a wide range, however, in what is marketed as herbal medicine. The effectiveness of botanical medicine necessarily depends on the quality and vitality of the original plant material and on the care and attention brought to harvesting, processing, and storage. These issues are crucial to the quality of any product we consume; they are especially important when we use remedies as medicine for healing.

As the natural products industry has grown—it was measured to be $5 billion in the United States alone in 2009—compromises have been made along the chain of production that undermine the integrity and efficacy of the medicines produced…