Either. If from seed I would maybe start it in a place you can keep an eye on it until it gets big enough to handle the wild.
Another good soil conditioner is to seed your plot with nematodes and fungus from a hardwood forest.
Find a healthy old growth forest, fill a bag with some dirt, then take it home and run water through the dirt to wash off the nematodes and fungus spores (a big strong teabag would be ideal) then water your plot with this water (don't let it go anaerobic) especially around your comfrey or other perennials.
This will be great for your soil condition after a year or two.