Wisteria, an ornamental member of the pea family, produce quick vertical coverage to trellises and fences. A perennial plant, wisteria produces white, pink or blue flowers along vines that reach up to 25 feet high. Proper pruning is vital, otherwise wisteria tends to become overgrown and unkempt looking. It can also overtake neighboring plants if left to sprawl. Wisteria benefits from twice yearly pruning, usually in summer and again in late winter when the vine is still dormant.
Prune the side shoots from a single strong vine on each newly planted wisteria. Tie the remaining shoot to the trellis with a plant tie. Tie the main vine to the trellis, allowing new side shoots to form and twine themselves to the trellis crossbars, but prune side shoots that do not grow in near the crossbars.
Trim off the ends of the side shoots on the crossbars of the trellis just beyond the seventh set of leaves. Cut off the new shoots that grow from these trimmed ends just above the first set of leaves that form on them. Continue to prune in this manner throughout the summer growing season.
Cut back the upright shoots to half their previous height in late winter or early spring when the wisteria first begins to show new growth.
Cut off suckers, which are new shoots that form at the base of the wisteria, in fall or late winter. Remove these at the soil level so they do not form any new shoots.