Few plants can boast as many niche filling functions as Comfrey; which is why I have well over a hundred around the farm and in my food forest (so far).
Less than half of those were purchased or dug up from elsewhere though, thanks to its amazing ability to propagate.
I have Symphytum officionale –the pure species propagated from seed. But the majority of my Symphytum legion are the sterile bocking varieties (a cross between S. officionale and uplandicum). No seeds.
Then there’s the normal method of propagation, dividing the roots. I often get a whole ten plants from one when doing this –the original of course coming back without any attendance. I’ve only done this with two plants though.
I much prefer this method because the only loss in mulch production and time is the loss of a few flowering stems; whereas you have to wait most of the growing season for seed to ripen; and while waiting for the seed the plant can’t be cut.
Digging disturbs the soil and puts the parent plant out of production until it resurfaces. Although I have to admit that isn’t long. Overall it just takes less effort to throw a few choice stems into a jar and let them grow roots.
In the jar, usually there is a fifty percent success rate for root growth. I have had further losses after potting up, but usually it is one hundred percent success once potted.
Just to illustrate how easy cuttings can root, I have had success just removing the developing flowers from a stem, sticking the stem directly under some fresh mulch, watering, and leaving. Mind, this was in the willow garden, so it was a good situation to begin with. Even compared to the other Comfreys in the willow garden, the resulting plant has been one of my best.
It’s just another plus of Comfrey that besides all its uses, it’s easily gotten.