I placed an order with Coe's Comfrey (in NC) today for 10 comfrey plants. This will be my first purchase of a dynamic accumulator. I am excited. I will spend the time while waiting for them to come digging the planting holes for them and amending the soil with compost.
This is the non-spreading Russian comfrey, Bocking #4 I believe.

While I was at it I ordered some October beans from the Sustainable Mountain Agriculture Center. They sound like a great old-style cranberry bean.