The kidneys are paired retroperitoneal structures that are normally located between the transverse processes of T12-L3 vertebrae, with the left kidney typically somewhat more superior in position than the right. The upper poles are normally oriented more medially and posteriorly than the lower poles.
Growing Comfrey in Pots. Comfrey will grow in pots (at least 3 gallon), containers such as plastic tubs, or 5-gallon plastic buckets but they do better when not grown in a pot. They have deep roots so prefer growing in the garden where they get more nutrients. The containers need drainage holes in the bottom. Add fertilizer to the potting soil.
Comfrey leaf constituents include tannins, rosmarinic acid, allantoin, steroidal saponins, mucilage, inulin, pyrrolizidine alkaloids, Gum, Carotene, Glycosides, Sugars, Beta-sitosterol, Triterpenoids, Vitamin B-12, Protein, Zinc. It is used in herbal pastes, ointments, tinctures, decoctions, poultices and in cosmetics. It is a popular addition to herbal salves and ointments, which can be used for bruises, sprains, eczema, swellings and burns. Research seems to bear out the claims for the healing properties of comfrey leaf.