All About Butterfly Bush

Butterfly bushes are abundant flowering shrubs. Starting in midsummer, on new wood that grew in spring, they flower until frost, producing blooms in a wide range of colors. The flowers also have a honey-like fragrance that's strongest at midday. There are many butterfly bush varieties available to grow. The most common types are in the Buddleia davidii group. Hailing from Tibet and China, these are the most cold hardy. These hybrids grow 6 to 10 feet tall and generally are hardy in USDA zones 5 to 10. Varieties include 'Black Knight' with its graceful branches and deep-purple colored flowers, 'Harlequin' with its rose-purple colored flowers and cream colored margins on the leaves, and 'White Bouquet' with very fragrant white blooms. Some dwarf versions of this group include 'Sky Blue' with light-blue colored flowers and 'Hot Raspberry' with raspberry-pink colored flowers. Both varieties grow on 3- to 4-foot tall plants.

There are other species of butterfly bushes from around the world worth trying. Lindley's butterfly bush hails from China with green leaves, cinnamon-colored bark and 2 foot long lavender colored flowers. It can be limbed into a small tree. From South Africa comes the Loricata butterfly bush that has white or pale-yellow colored flowers. It's unusual in that it flowers on old wood, so should be pruned after the first flush of blooms in summer. Snow White butterfly bush also hails from China and can grow 15 feet tall with pale, lavender-colored blooms.

Keeping up with the deadheading can be a challenge on these larger shrubs since they flower so well and the dead flowers are unsightly. To avoid the problem of self-sowing, try to deadhead consistently all summer not letting the seed to set.

Butterfly bushes are considered invasive in some states (Oregon, Washington, and Hawaii), so care should be given to not let them spread into the wild. Where they're native, they're a pioneer species that moves into open, sunny disturbed lands. They can set millions of seeds in one season. In the wild, the plants eventually get crowded out by taller growing shrubs and trees. In the garden, these seeds can be a problem without these natural controls in place. While deadheading will help, growing varieties such as 'Blue Chip' and some species types such as Buddleia fallowiana that have sterile seed or low-viability seed, will reduce the threat. Butterfly bushes are less weedy in colder climates.