But in January, once all the leaves have died away, you do another once-over of the whole plant. This second prune shortens all the growing stems back to about a hand's length of the main trunk and branches.

The objective of the second hard prune is to get the world's prettiest shape, even when there are no leaves on it, and also to force the wisteria into flowering profusely.

I took this springtime photo in France two years ago and it shows the absolute ideal as far as I'm concerned: a beautiful twisty trunk and branches, about to burst into thousands of racemes of flower (you can click on the picture to see it in more detail).

It's no wonder that the wisterias come from China and Japan where the beauty of a gnarled trunk like this is much appreciated. But I am determined to master the art of the wisteria this year, involving me and my secateurs in many shaky ladder moments. But by pruning hard and often like this, not only do you get a better shape and flowers; you also keep the wisteria out of the roof tiles, gutters and chimney pots, where it can really do some damage. Even this classy and well-controlled French example is showing the unquenchable wisteria desire to wreck some exterior fittings.