I'm no clematis expert - you'd find those on the clematis forum, which I highly recommend, and where I did post a link to this question - but no, you should not have to rip up the whole garden.

You should divide this task into two objectives: one is transplanting a piece to get it started in a new spot, and the other is eradicating from the old spot.

How you tackle this depends somewhat on how the clematis grows. I assume there are a bunch of shoots coming out of the ground over a large area. Alternatively, there might be one trunk or point of origin from which shoots continue to sprout.

If it is the former, then you have probably got a Type C clematis and perhaps you can just divide it like any perennial - take a chunk to the new spot and nurse it till established. (Or, given that it is midsummer, put it in a large pot in the shade and neither over nor underwater).

If the latter format is what you have, then you should just concentrate on getting the trunk part with a reasonable amount of root, so it can survive.

Once you have it established somewhere else, you can start just yanking any shoots at the old spot that come up, and after a couple of years the original plant should die. Or you can do a major excavation to get it all out once and for all.

All this digging is facilitated if you use not just a shovel, but also some clippers, loppers, or maybe even a saw to get through the roots so that you keep some attached to the clump you are digging up to save, and so you can remove whatever you can get without having to chase the remaining roots to China.

KarinL

They have big root systems, some bigger than others. Some can be downright weedy.

I'd cut it back to about a foot tall and then start digging a couple of feet out from the crown.