Summer Pruning

• When beginning to train wisteria, summer pruning helps train the young vines and encourages the plant to bloom the following year. In July, select the strongest, most vigorous leader from the growing shoots. Cut off the remaining shoots. Attach the strong leader to the support structure, allowing it to grow up the structure and form healthy branches from one strong leader vine.
  
  

Winter Pruning

• Some wisteria gardeners recommend severely pruning the vines back each winter, however this can compromise the plant's ability to bloom, because it produces blooms on 1-year-old wood. Also, drastic winter pruning causes the plant to emerge with wild, difficult-to-control growth in the spring. Instead, prune shoots off the leader branch back to one-half or two-thirds their current length. Cut off any side shoots to a length of about 1 inch long.
  
  

Pruning Established Vines

• After a season of proper winter and summer pruning, engage in bi-annual maintenance pruning. As the vines become established in the landscape it becomes easier to control the wild growth habits of wisteria. Each summer, prune off any side shoots or growths that threaten the strength of the wisteria's central leader. In the winter, prune shoots back to for or five buds. Remove any suckers from the base of the wisteria plants.
  
  

Root Pruning

• Most gardeners plant wisteria for their impressive, fragrant blooms. However, very young plants and old vines occasionally experience issues with blooming. Pruning roots in the autumn sometimes helps restore blooming. Draw a circle in the soil, about 4 feet from the main trunk in all directions. Use a space to slice roots vertically. Typically, wisteria roots grow about 18 inches below the soil surface. Engage in root pruning in the autumn, prior to the season's first winter frost.