Comfrey roots and crowns should be planted immediately or kept refrigerated until planted. Never put them in the freezer!
Each piece will grow into a new plant. Plant comfrey roots in well-drained soil in a sunny location. Plant roots about 1” deep. Lay the roots horizontally, do not plant them vertically. For crowns, make sure the bud (if there is one) is pointing up. The buds should be just under the soil surface. If there is no bud, the root will grow a new one. Mulch well with hardwood leaves, wood chips, grass clippings, etc., about 1” to 2” thick. Keep the soil moist, but not wet, and also weed-free, until plants are well established.
That’s all there is to it!