I had to give it up when we moved. I was doing Bocking 4. Had hundreds of them that I had propagated from a dozen root cuttings. nostr:npub1ugnq57hn8va6xqr5zywy2eunem6c624583vkt0dmv40ep7tnnxkqrr898l has my root stock now so I can vouch for his Bocking 4 line. He also has Bocking 14 which is better for forage.

Here is the episode I did on comfrey:

https://fountain.fm/episode/15491737864