Russian Comfrey - 5 Live Root Cuttings - Bocking 4 - Comphrey - Knitbone (5) Non-invasive Bocking 4 cultivar of comfrey, which will not produce viable seed which may spread uncontrollably. Though of course comfrey can always spread from roots. Be careful about tilling a comfrey patch! Bocking 4 comfrey is the most desirable cultivar for making a tea or compost to fertilize your garden, With an NPK ratio 1.8 / 0.5 /5.3. Comfrey is a dynamic accumulator of nutrients from deep in the soil, most notably iron, silicon, nitrogen, potassium, calcium, magnesium. Also many trace minerals. Ask your doctor about the many medicinal benefits of Allantoin from comfrey, especially bone fractures, sprains, wounds, bruises, ect. Save money on animal feed! Comfrey is used worldwide as an animal fodder. Dried comfrey leaves contain 26% protein. Although some animals enjoy comfrey fresh, if you find your animals do not like fresh comfrey, offer them comfrey which has wilted for a day or dried completely. Comfrey is the only plant which harvests vitamin B-12 from the soil! Choose Yumheart Gardens comfrey root in confidence knowing ours is grown organically and is free from disease and pests.