It's illegal to dig up roots without landowner's permission.....and JKW is such a problematic pain that any poor blighter who has it inflicted on his/her land must already feel the stress of it and be 'really' concerned at any potential spread.
On t'other hand, the tops if picked constantly, especially in the growing season, are both good food and slowly starve the roots to death.
Takes a lot of eating though.
I cook every part I take, even the stuff I'm not going to eat. That way I know I've killed it.
The lower stems are pretty cheugh, can't imagine the roots would be any softer.
I don't take the roots though, it can literally grow from a tiny tiny piece. I wouldn't advise anyone else to take them either.
It's rather a triffid of a plant.