How Far Are You Supposed to Cut Butterfly Bushes Back?


Butterfly bushes, also known as Buddleia species, are well named because of their ability to bring large numbers of colourful flying insects into a garden. According to the Missouri Botanical Garden, the shrubs may thrive in USDA plant hardiness zones 5 through 11, depending on the type. There are two distinct techniques for trimming Buddleia (which can also be called Buddleja), and both are dependent on the species. Be careful to write down the names of your butterfly bushes when you plant them so that you can determine how much and when to prune them each year. This will depend on the type that you are cultivating.

Butterfly Bush Care

Butterfly bushes need full sun and wet soil in order to thrive, and their mature height may range anywhere from 5 to 15 feet. The flowers typically bloom from summer through autumn at the terminal ends of branches in clusters that are called panicles and range in length from four to ten inches. They bloom in multiflower panicles in a variety of colours, including hues of pink, purple, blue, and yellow. In regions with mild winters, the branches may eventually become woody and only produce a few flowers at the very tips. In areas with harsh winters, the plants may wither and die back to the ground, but come spring, they will revive themselves from their roots.

Pruning Buddleia Species When Dormant

The most popular form of butterfly bush, which belongs to the species Buddleia davidii and can be grown in USDA plant hardiness zones 5 through 9, blooms on new wood and receives the majority of its pruning in the late winter or early spring, when new buds begin to appear in warmer climes. If you prune this plant before it has gone completely dormant, you risk killing a plant that might have survived the winter otherwise. Reduce the height of the plant so that it is between 8 and 10 inches tall. This will help control the growth of the shrub and will also stimulate flowering. New shoots sprout from the base of the butterfly bush plant in the places where the plant has died back to the ground. Lophers or hand pruners should be used to remove any old, woody vegetation that is present in the area.

Pruning Buddleia Species After Blooming

Blooming in late spring or early summer on the previous season’s growth, tree lilac (Buddleia colvilei), fountain buddleia (Buddleia alternifolia, USDA hardiness zones 5 through 9), winter-flowering lilac (Buddleia asiatica, USDA hardiness zones 7 through 10 according to Plants for a Future), and orange ball tree buddleia (Buddleia globosa, USDA hardiness zones 6 through After the plants have flowered in the early summer, you should prune these butterfly bushes. Removed branches that had blossomed and returned them to their base. Eliminate any branches that are either dead or crossing. Do not disturb the growth of this season since it will produce flowers in the next year.

Curbing Invasive Tendencies

Butterfly bush is a plant that should be monitored even in regions of the nation where it is not expressly classified as an invasive species since it is deemed invasive in some regions. It is easy for volunteer plants to spread from seed, and it is normal for new bushes to appear in other sections of the garden, in natural areas, and in the spaces between concrete slabs that are used for walkways, patios, or driveways. It is a good idea to remove fading blooms from plants in late summer and autumn before they create seed heads. Although vigorous pruning in the fall might cause plants to die back during the winter, it is a good idea to deadhead them. Deadheading removes faded flowers. Because of this, there is a possibility of another cycle of blooming, which requires careful monitoring on your part.