How to prune ninebark 'diabolo'

Early spring, before new growth begins. Each spring, cut one-third of the oldest, thickest stems to the ground to stimulate fresh growth. Shorten the remaining stems by up to one-quarter to shape. For full rejuvenation, cut everything back hard to 6–12 inches — Physocarpus re-sprouts vigorously.

Annually. Ninebark 'Diabolo' responds well to annual pruning to maintain size and encourage vigorous dark-purple foliage. Prune in early spring before growth starts. Remove one-third of the oldest stems at the base each year (renewal pruning). It can also be cut back hard for rejuvenation and recovers quickly.

Each spring, cut one-third of the oldest, thickest stems to the ground to stimulate fresh growth. Shorten the remaining stems by up to one-quarter to shape. For full rejuvenation, cut everything back hard to 6–12 inches — Physocarpus re-sprouts vigorously.