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 root has been used since Roman times, dating back thousands of years. This herb has been utilized in folk medicine throughout Europe and North America and has been widely cultivated as a garden medicinal specifically for its reputation for healing various internal and external wounds.