DO NOT GET SEED!!i need to get me some comfrey seed. any particular varieties you like @greasemonkeymann ??
The 'wild' comfrey is extremely invasive and all comfrey is next to impossible to kill. What you want is Bocking 14, a sterile variety that stays put, but extremely easy to propagate. You buy either crowns or chunks of roots and plant in a permanent location. They don't do all that well in pots long term, but Ok for a time while you figure out their 'forever' place in the yard.
My main worm food is comfrey and coffee grounds. You can cut it at ground level and it will be ready to cut again in a month. It grows that fast.
"Land Kelp" is a very apt descriptor. GMM will attest to the same.
Wet