How to prune wisteria
Having finished its spring flowering, wisteria makes rampant growth now with long, whippy shoots; they need pruning back at midsummer before they become overbearingly tangled.
Cut back the trailing, wiry stems now, to leave four or five leaf-joints remaining on each stem. (Wisterias need twice-yearly pruning: the next time will be in midwinter, when you will be hard-pruning to get good flowering spurs; alas, it cannot all be done at once right now.)
