Crown cuttings establish much faster than rootlets. Bocking #4 comfrey is excellent for fodder and can be used medicinally. This hardy cultivar is sterile and will not spread through self-seeding.  Use fresh or dried to supplement animal feed.  Large leaves can be pruned or snapped off as needed throughout the growing season.  Remove any flowering stalks to keep comfrey producing large leaves during the growing season.  Does best when watered regularly for production.  
 
Excellent as a "chop and drop" mulch for fertilization, or make a compost tea for plants.  Easy to plant; just place the cutting with the growth point up, covering the crown with 1-2 inches of soul and water regularly.  Vigorous grower, should be divided every few years to maintain the health of the plant and expand your comfrey plantings... or just share with a friend!