Last spring, I planted a comfrey (symphytum officinale) plant into one of the hugelkultur beds. The plant was from a 4″ inch pot from Rolling River Nursery (www.rollingrivernursery.com). Since it was such a relatively small plant, I did not expect too much of it the first year. It ended up growing fairly well and leaves reached over a foot in height plus a few extra inches for a couple flower stalks with pretty purple-ish flowers.
Comfrey is pretty highly revered in most permaculture circles due to it’s nature as a dynamic accumulator – a plant that will actively take up and retain relatively high concentrations of minerals from the soil. This link has a nice table showing which minerals are concentrated by different plants:
Comfrey also has a reputation for being able to quickly grow a strong and deep root system, which probably helps it mine the soil for nutrients. This characteristic, coupled with the ability to grow a new plant from small pieces of roots also has given comfrey a dangerous reputation as a potentially troublesome plant if placed too close to an area that receives regular cultivation.
This is the time of the year to divide the comfrey in our part of the world. The crown of the plant is just getting started in sending up some new leaves, making it easy to tell where to subdivide the crown. I started digging away the loose dirt around the crown with my hand and quickly found my first root about 6 inches down. It was almost an inch across and continued on much deeper. I gave up after going down a foot and pried up the crown and root mass:
Given the size of the crown and the number of nice thick roots, I am very happy with the first year growth. I cut the crown in to several pieces and planted them in new locations in the hugelkultur beds. The remaining roots were cut in to 1-3 inch pieces and planted a few inches deep across all seven hugelkultur beds. If they all make it, there will be nearly a hundred comfrey plants soon!
This year, I will start using the leaves of the comfrey each month to fertilize the fruit/nut trees and bushes. Each month, most of the leaves will be cut from a plant and tucked under the mulch under a tree or bushes drip line. This way, the nutrients accumulated by the comfrey from deep in the soil benefit all of the orchard.