I have a new Blue Moon wisteria (when purchased it was about 1 meter high) that was planted in May and has reached the top of the pergola, twining around a support. Now it has nothing to climb on to, the climbing vine has extended out about a meter at the top of the pergola and is swaying in the breeze. It doesn’t seem to be growing anymore. Should I just leave it, or should I try to help it along? I have to admit I am loathe to get up on a stepladder to try to pin it down in any way, but if that is what is needed I’ll do that (with someone to spot me).
Wisteria typically produces volumes of long, whippy leaders, like yours, happily climbing and travelling where they can. If your swaying shoot might ultimately add to the overall look of the wisteria, then tying it to trail across the top of the pergola could be a good idea. Alternatively, you can leave the shoot as is, to continue blowing in the wind, searching to attach itself to a surface. Either way, you can always train, or prune, next season.
However, many gardeners prefer to prune wisteria back to promote flowering. Trace back along its secondary stem to 5 buds (where leaves sprout out), from where it meets the main stem, and prune. This will help encourage the shoot to become a flowering spur, and focus its energy on forming flower buds, not green growth.
For additional information, please see a previous post – Ask a Master Gardener. Wisteria training and pruning.
And Garden Ninja’s How to prune Wisteria: Winter & summer pruning guide for beginners has terrific photos that illustrate how to prune/train wisteria.
As well, for your research, there are several good YouTube videos that discuss pruning/training wisteria.
All the best with your lovely vine!