Deciduous vines, like shrubs, benefit from pruning. Occasionally it is necessary to limit growth, improve flowering, or remove deadwood or weak stems and branches. Vines respond like other landscape plants to pruning. Always prune back to a lateral branch, twig, or bud and do not leave a stub. Cut dead, weak, and thin branches back to healthy, vigorous stems. Annual thinning encourages new growth and continual rejuvenation. When stems grow too crowded, cut back some of them to the ground.
Most vines respond best to pruning in the late dormant season, before spring growth begins. Prune early-spring flowering vines after blooming to encourage maximum bud set on new growth. Every year in early spring cut back to 6 to 8 inches above ground vines that flower on new wood — for example, many types of clematis.
Fast-growing vines require yearly pruning. Some particularly vigorous vines will overwhelm a garden, develop a barren woody trunk, or become overcrowded if not kept in check. Cut back these vigorous growers severely to induce new growth close to the ground. This is not harmful as long as it is done before spring growth begins. Contain fast-spreading vines such as Boston ivy by cutting stems to the ground, heading to a bud, or thinning to a lateral.
When a vine becomes unmanageable from lack of yearly pruning, cut it to the ground and let it start over. When the new stems appear, select the most desirable and remove the rest. Pinch the tips of climbing stems to slow their upward growth temporarily.