Making comfrey feeds

[jojo2910]

I meant roots.

[sadowska]

how about lungwort?

somebody mentioned borage was an alternative to comfrey for making feed. How about lungwort? I have loads of it (as well as some comfrey) so was wondering if I could use it for a potash fertiliser. I think I read, although could be wrong, that it's of the same family as comfrey and borage with a long tap root which draws up the nutrients. Would this work do you think?