The Butterfly Bush, scientifically known as Buddleia davidii, is a popular garden shrub recognized for its vigorous growth and ability to attract pollinators, especially butterflies. This plant is a favorite of gardeners looking for summer-long color and activity in their landscape. To accurately identify this fast-growing shrub, it helps to understand its general form, the structure of its blooms, and the specific appearance of its foliage and stems.
Growth Habit and Overall Size
The Butterfly Bush typically establishes itself as a large, multi-stemmed woody shrub, characterized by a rapid growth rate. In ideal conditions, the plant can reach heights between 6 to 12 feet, and spread nearly as wide. Its overall silhouette often takes on a bushy, rounded form with a distinct arching or weeping habit to its branches.
This vigorous growth can sometimes result in a sprawling or slightly messy appearance if the shrub is not regularly pruned. In colder climates, the plant behaves more like an herbaceous perennial, where the above-ground stems die back significantly or completely to the ground during winter. The root crown is hardy and sends up vigorous new growth each spring, on which the summer flowers will appear.
The plant’s classification as a deciduous or semi-deciduous shrub depends on the mildness of the local climate. In regions with moderate winters, the plant may retain some of its foliage, while in colder areas, it sheds all leaves completely.
Distinctive Flower Spikes
The most recognizable feature of the Butterfly Bush is its floral display, which occurs throughout the summer and into the fall. The flowers are clustered into long, dense, cone-shaped terminal spikes, scientifically known as panicles. These showy flower clusters often measure between 6 to 12 inches long, sometimes longer in cultivated varieties.
Each panicle is composed of dozens of tiny, individual florets that are tubular in shape and possess four small, spreading petals. The flowers are known for their sweet, honey-like fragrance, which is a major draw for various insects. The wild species typically features lilac to purple blooms, often with a small orange or yellow throat at the center of the floret.
Cultivation has introduced a broad palette of colors, expanding the visual range to include pinks, whites, deep magentas, and even yellows and near-reds. Since the blooms are produced exclusively on the new growth of the season, a steady supply of new flower spikes emerges from late spring through the first frost. Removing spent flowers, known as deadheading, encourages the plant to continue producing these fragrant spikes for an extended period.
Leaf Shape and Stem Appearance
The foliage of the Butterfly Bush provides a textural contrast to the blooms and helps in its identification when flowers are absent. The leaves are arranged oppositely on the stems and possess an elongated, narrow, lance-like shape. They typically measure between 4 to 8 inches in length with finely serrated or toothed edges.
The color of the leaves is generally a grayish-green or sage-green on the upper surface. A distinctive feature is the underside of the leaf, which is covered in fine, dense, woolly hairs, giving it a silvery or whitish, felt-like appearance. This soft, fuzzy texture is also present on the younger, square-shaped branches.
The stems and branches of the shrub are woody. Younger shoots are often greenish and covered in the same fine hairs as the leaf undersides. As the wood ages, it develops a more mature, brownish or tan coloration, and the bark on the older, main stems can become slightly flaky or fissured.