I've never seen comfrey available locally. I found mine on line, the first time from a generous member of of ATP/Cubits and the second time (the plant I have now) from an on-line plant source. I do recommend my on line plant source, as I have bought many plants from them over the years and I'm always happy with them. Ironically, the name of the company is Companion Plants!
They're in Ohio. Here's the link at our Forum of Recommendations:
http://garden.org/reviews/view...