While it is easy to grow, wisteria does require some dedicated care. Wisteria is a lovely vining plant with cascading blooms of lavender or blue-violet flowers and distinct fragrance. Most importantly, wisteria needs regular pruning, or it can take over everything in its path.
Wisteria needs full sun and a large area in which to grow. It also needs support in the form of a fence, deck railing, wire attached between supports, trellis, arbor, pergola, or other form of support. It doesn't tolerate cold well, although it is a perennial. Make sure it is planted in rich, well-draining soil.
Training Wisteria Vines
The first step in training a wisteria vine is knowing which way it twines. Chinese wisteria twines in a counterclockwise direction, while Japanese wisteria twines in a clockwise direction. To train the vine, select a healthy upright stem and prune off any side shoots.
Attach the stem with a soft ties to the support. At roughly 18 inch intervals, as the vine grows, attach the top of the vine to the support. Cut off all side shoots except for those you plan to train across the supporting structure. Train these shoots to the supporting structure following the natural twist of the vine. For best results, keep side branches spaced about 18 inches apart. Continue in this way until the vine has reached the top of the support. Once the vine has reached the desired height, pinch off the top of the stem to stop it from growing. This will force growth along the side branches.
Prune wisteria heavily in late fall or winter. Cut out all dead or damaged wood and crowded branches. Trim the side branches back to within a foot of the main stem and clear out any stray suckers. During the growing season, cut out new shoots to keep the vine in check.
Once the blooming season passes, wisteria puts its energy into sending out new shoots. If you are still training your vine, select the best shoots and attach them to the support system by twisting the tendrils around a wire or other structure in the natural direction of the vine's twist. Cut out all other shoots. These trimmed shoots will become next year's flowers. It's important to stay on top of this during July and August in order to force new shoots into flower producing stubs. If you don't do this, you will end up with a twisted mess that will be hard to care for the following year.
Cut the stubs back to about six leaf joints away from where it attaches to the main stem. New growth will quickly appear and this needs to be trimmed back to within two leaf joints. Continue in this way throughout the rest of the growing season.
Wisteria is aggressive and drought tolerant. For this reason, it will need very little watering. It does not require fertilization.