Di Dao doesn't translate easily into English, like many of the great Chinese concepts (e.g., Jing, Qi, and Shen!) The word Tao, in this case, refers to the district in which the herb is grown, and Di is more to do with the soil and land in which the herb is grown. In other words, sourced from its spiritual homeland. Di Dao herbs must be high quality, medicinally dense herbs that have been grown in their natural habitat. This provides the herbs with the healing properties that allow them to be effective in fulfilling their purpose as medicinal herbs and tonics.
Ron Teeguarden, founder of Dragon Herbs and legendary tonic herbalist, translates Di Dao to "Earth Tao," or "the Way of the Earth." He says,
"Every plant has its perfect habitat where the plant flourishes, and in the case of a herb or food, becomes the most phytochemically rich and balanced."
Chaga grown on birch trees in a forest in Siberia and Chaga grown indoors in a lab in a temperature controlled, light controlled environment are different. Medicinal Mushrooms impart a lot of their benefits from the wood that they grow on. (In comparison, most indoor grown mushrooms are grown on starch or oats).
Wild herbs possess more power and potency than cultivated herbs. Wild herbs must survive naturally even in extremely harsh climates. Cultivated herbs can sometimes be weak and fragile, and therefore lack inner power. That will be reflected in the price of an herb, in its flavor, and most importantly in its efficacy. Cheaper brands always use weaker cultivated herbs, often from non-Di Tao growing sites.
China has one of the longest-standing herbal traditions in the world, and one of the oldest books on medicinal substances (also known as a "materia medica") in the Shen Nong Ben Cao Jing, which was compiled in the 1st century AD during the Han dynasty. Di Tao is acknowledged by the Chinese government and recognized by modern TCM (traditional Chinese medicine) practitioners too.