The same asparagus sharing friend also sent me home with a clump of comfrey. I've planted it next to one of the cherry trees and can't wait for it to start spreading. I plan on using it as fertilizer and in my compost piles. (I decided not to plant it in a way to contain it, D, I decided that I would go ahead and let it spread - all the better to use and share more. Could those be famous last words??)
There is a blurb about comfrey here that I like...not too sure about the bit warning that comfrey fertilizer will smell like open sewage. Neighbours might not like that!!