The poster has received four sources for comfrey, so doesn't need any more. However, I have found from reading the answering posts that if you have comfrey, you have comfrey for life!

Yeah.....I've heard that about comfrey as well as horseradish. I have read that if you move the plant or disturb the ground too much around comfrey, that is when you get new baby comfrey plants sprouting from rootlets. So pick the location well and leave be...

FataMorgana

a source is touting comfrey as the next super plant. It supposedly has all of these production properties so there may be more questions popping up on the various groups. I did not remember that it was one of those forever plants. Until I realized who the email was from I deleted as spam. Good person but on the fringe.

Comfrey is used in the UK a lot as a natural fertilizer. You grow a patch separate from your other plants--because it is an aggressive critter--and you harvest the tops and either dig them in to your soil or compost them. I'm going to try it this year. It's not fringe, just hasn't been done here a lot.

I have it, it is not impossible to get rid of, you just have to be very persistent. I don't have it in my original position but moved it to a place by the woods, but it has seeded itself in a couple of other places some distance away. I haven't tried it as a fertilizer or compost aid. I made salve out of it last year, it is easy, covered with olive oil in a mason jar set in water in a crock pot, then strained through nylon mesh. I added various other herb oil infusions, and stiffened it with beeswax in a double boiler.

It is in the borage family, borage is an annual but comes up quite aggressively every year in my beds where I grow squash and tomatoes. It is great for attracting bees to the squash blossoms. I imagine it would also be a good compost aid, green manure, whatever.

I also have a ground cover comfrey, Symphytum grandiflorum, it stays low and is very useful in an orchard under fruit trees since it is one plant that is actually tougher than most grass except one big clumper I'm fighting. I can still see fallen apples pretty well in it. It keeps me from having to cut grass or weed under my fruit trees.:-) It also is planted on a bank over a ditch that is never watered, and has done quite well, even spreading across the ditch. I used to have to try to use a weed trimmer on grass and weeds on the bank but now the only persistent problem is the Himalayan blackberry vines. I also use it in very dry shade under tall cedar trees, and it does well.