About 5 years ago I planted a Wisteria sinensis in my yard. I was going to build a trellis to support it, but got busy every year and did get to it. This year I decided to redesgin my garden and want to move it to another spot, do they transplant well? And how would you do it? How much of the vine would I take off for transplant?
Prune it to match your new support system. It may be best to disassemble the existing trellis, sort of, with the purpose in-mind of saving the interwoven branches that suit your next site. That is to say: rather than cutting the branches off where they are trapped on the trellis, cut the trellis instead, freeing the branches. If you can do the preliminary digging with the fork to soften the ground so you can know where the anchor roots are to the point that you can lift the whole root system out when you have freed the branches from the trellis, or freed the trellis from the fence, then you can drag the whole mess out to a place where you can cut the rest of the trellis free without damaging the branches of your choice, and doing the same choosing of roots you want to keep. Keep less roots than branches. Cut out more roots than you cut off branches. Never feed it. The foliage is very soft and breaks easily, but that won't matter much. Since they grow too much and too fast anyway, it's better to prune the roots more than you prune the top. Otherwise, you will get a million new branches emerging from the base. It is probably grafted on lesser rootstocks so the new shoots from the roots wouldn't be your special cultivar. Look for the graft. Replant with the graft out of the soil. Watch for these errant, prolific bull canes growing as suckers in every direction for the rest of your life and prune, sooner rather than later. Never feed it. Over time, you will prune the branches for shape while not pruning the roots. The roots will grow as much as the branches, but since you're pruning the branches, reducing the volume of branches while not reducing the volume of roots, you will eventually have an imbalance. The roots will compensate by growing wherever you're not looking. You can shortcut this imbalance by root-pruning every couple years. It's very simple: Sink a spade as deep as the spade is in a circle all the way around the perimeter of the rootball, maybe 24" out from the trunk severing all the roots at that line. That will keep the balance and even result in the opposite imbalance which is very good. You want some growth, but not the whole enchilada every year. Never feed it. And that's all there is to it.
At the moment the critical point is to wait until it sheds its leaves this fall before digging it up.
