I have several butterfly bushes that I didn’t trim last fall. They got really big. When is the best time to trim them between now and spring? Also, how far down should I take them? Thank you!
The Gardener’s Answer
Hi, Angela: It is good thing that your Butterfly bush (Buddleia davidii) did not get pruned last fall. As a general rule, summer-flowering shrubs should be pruned during the late winter or early spring, before new growth begins. Pruning at the end of the growing season could expose tender new growth to frost damage. Butterfly bush bloom on new wood (current season’s growth) so they can be pruned back hard. Ideally, you want to cut them back to around 12 inches annually. This seems drastic but Buddleia are tough plants that respond well to hard pruning. They are woody near the base of the plant but produce new herbaceous growth year after year. Remove crossing branches and thin out if needed to increase air circulation. Proper pruning rejuvenates, encourages new growth, and larger flowers. Removal of spent flowers during the growing season will promote blooming throughout the season and into the fall.
Kentucky Living-Ask the Gardener