Buddleja - Cultivation and Uses

Cultivation and Uses

As garden shrubs Buddlejas are essentially 20th-century plants, with the exception of B. globosa which was introduced to Britain from southern Chile in 1774 and disseminated from the nursery of Lee and Kennedy, Hammersmith. Several species are popular garden plants, the species are commonly known as 'butterfly bushes' owing to their attractiveness to butterflies, and have become staples of the modern butterfly garden; they are also attractive to bees and moths. Some species of South American Buddleja have evolved long red flowers to attract hummingbirds as exclusive pollinators.

The most popular cultivated species is Buddleja davidii from central China, named after the French naturalist Père Armand David. Other common garden species include the aforementioned B. globosa, grown for its strongly honey-scented orange globular inflorescences, and the weeping Buddleja alternifolia. Several interspecific hybrids have been made, notably B. 'Lochinch' (B. davidii × B. fallowiana) and B. × weyeriana (B. globosa × B. davidii), the latter a cross between a South American and an Asiatic species.

Some species commonly escape from the garden. B. davidii in particular is a great coloniser of dry open ground; in urban areas in the United Kingdom, it often self-sows on waste ground or old masonry, where it grows into a dense thicket, and is listed as an invasive species in many areas. It is frequently seen beside railway lines, on derelict factory sites and, in the aftermath of World War II, on urban bomb sites. This earned it the popular nickname of 'the bombsite plant' among people of the war-time generation.

Popular garden cultivars include 'Royal Red' (reddish-purple flowers), 'Black Knight' (very dark purple), 'Sungold' (golden yellow), and 'Pink Delight' (pink). In recent years, much breeding work has been undertaken to create more compact buddlejas, most recently the production of dwarf varieties such as 'Blue Chip' (Lo & Behold™) which reach no more than 2–3 ft (0.61–0.91 m) tall, and are also seed sterile, an important consideration in the USA where B. davidii and its cultivars are banned from many states owing to their invasiveness.