This is a case where I make an exception to my mostly-organic garden. I don't even attempt to dig multiflora monsters; it is literally too much of a pain. I use a stump killer such as Tordon. I know this is a potent chemical, but you can dig all day and not get all the roots of multiflora, and you'll have to do it all over again next year. That chemical follows the roots and gets all of it. It can't be used when the offensive rose is growing very close to desirable plants because occasionally roots will cross and the chemical could potentially move to the other plant.
