I put mine (divided one plant into 28) in an accessible patch that was easy to scythe all at once and take where ever. I'm sure we'll end up with multiple clumps of it on our largish site. Need to cut it multiple times a summer, and I'd rather not have to worry about cutting around something I don't intend to chop. I see maybe a chance of it spreading into blackberries where it'd be difficult to get to, and then it might flower and start seeding itself around the garden. If you let it flower and
seed unchecked for enough years, it really does seem to start to spread everywhere.
Around trees is usually good, as you can chop and drop it right where it lives. Comphrey is a good place to start, but here are other things, like mountain mint or bee balm, that would be better beneficial insect feeders. Varieties of
mulch makers are a good thing.