Dividing Butterfly Bush: How And When To Divide Butterfly Bush Plants

Several Purple Butterfly Bushes
butterfly bush division
(Image credit: Robitaille)

It is understandable that gardeners love butterfly bush plants (Buddleia davidii). The shrubs are low maintenance, grow fast and – in the summer – produce beautiful, fragrant flowers that are attractive to bees, hummingbirds and butterflies. The sun-loving deciduous shrub is easy to grow and easy to propagate by seeds, cuttings or division. Read on for more information on how to divide a butterfly bush.

Butterfly Bush Plants

Butterfly bush plants are native to Japan and China and rise quickly to some 10 or 15 feet (3 to 4.5 m.) high, offering lush flowers in shades of blue, pink and yellow, as well as white. The flowers, presented on panicles at the end of branches, smell sweet like honey. Butterfly bushes are tough and easy plants, tolerant of drought, poor soil, heat and humidity. Since these shrubs grow rapidly and can reach a spread of 8 feet (2.4 m.), a backyard gardener may wish to divide the clump at some point.

Can You Divide Butterfly Bushes?

Dividing butterfly bush is one of the best ways of propagating the plants. It is entirely possible to divide healthy bushes as long as they are big enough. You may want to know when to divide butterfly bush. You can act at any time during the year as long as the plant is healthy, but many gardeners prefer to divide plants in fall, when the soil is warmer than the air at least part of every day.

How to Divide a Butterfly Bush

Dividing butterfly bush is not difficult. The process of division is a matter of digging up the roots of the plant, dividing them in two or more pieces, and replanting the separate divisions. But a few tips can make the process of dividing butterfly bush faster and more effective. First, it pays to soak the soil around healthy, thriving butterfly bush plants the night before you are to divide them. This makes removal of the roots much easier. The next morning, carefully dig up the roots of each plant. Use pruners or your fingers to divide the plant into several pieces, being sure that each “division” has a few roots and a few stems in it. Act quickly to replant the divisions. Replace one of the divisions back in the location where you dug it from. Plant the others in pots or in other locations in your garden. Do not hesitate in replanting the divisions, as the roots may dry out. Water all divisions well and keep the soil moist, but not wet, until the plants are established. You can fertilize if you wish to promote faster growth.

Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.