Wisteria is fast-growing, twining vine often grown on large trellises or pagodas. However, wisteria can also be training into a tree form, although it will require frequent pruning. Fortunately, because wisteria is so abundant with new growth, it develops into the form of a tree fairly quickly, and within a couple of years will thrive under its new-found shape
Select a young wisteria vine. Do not use a mature wisteria, as severe pruning can damage the plant, leave it prone to disease, and may eventually kill it. The best time to purchase a new wisteria vine is in the winter or early spring.
Plant the vine in a bright location that gets at least 6 hours of sun each day, at least 15 feet away from any plant, building, or object the plant may try to climb.
Cut off all the wisteria's vines, except the strongest one, using clean pruning shears or lopers.
Stake the single vine (which will become the wisteria tree's trunk) with a wooden or metal stake designed for growing young trees.
Cut off any and all new shoots that grow low on the tree trunk. Allow side shoots high on the trunk to grow.
Cut the wisteria down when it reaches the height you wish it to achieve--usually 4-5 feet high.
Replace the wooden stake with a 4-by-4 wooden post. This will help the tree survive strong winds and the natural tendency for the plant to fall to the ground.
Prune side shoots you wish to keep to about a foot long every winter until the tree has filled out as you desire.
Cut off any new, low shoots as the tree continues to grow, and in the fall, trim shoots you want to thrive by about half, to encourage new growth in the spring.