Passionflowers flower on the current years growth. Prune your plants in the spring as growth starts by removing older parts which have become untidy. New shoots will quickly sprout from other areas of the vine stems. Train these over a trellis or wires as soon as possible, as new ripened shoots are brittle. If not tied to their support soon enough they may break later. Many varieties will die back to the ground during winter, so pruning in these areas may not be necessary.