Horticulture/Buddleia

Buddleia, also often spelled Buddleja, is a genus of flowering plants. It is now included in the Scrophulariaceae, though in the past was previously classified in either the Loganiaceae or in a family of its own, the Buddlejaceae. The plant was named after the Reverend Adam Buddle who was a botanist and a rector in Essex, England. The name has been the source of some confusion. By the usual practice of botanical Latin, the spelling of a genus name made from "Buddle" would be "Buddleia". However, Linnaeus wrote it down as "Buddleja", and never changed it, so by the rule of naming priority, "Buddleja" should be preferred, though the i/j interchange could be modernized as an orthographical variant. Even so, the usage is confused, and inconsistencies are common, even within single texts

The roughly 100 species are mostly shrubs, a few being trees; the largest species reach 30 m (100 ft) tall, but most species rarely exceed 5 m tall. Both evergreen and deciduous species occur. They are native throughout the warmer parts of the New World from the southern United States south to Chile, and widely in the Old World in Africa and the warmer parts of Asia, but absent as natives from Europe and Australasia. The species are divided into two groups based on their floral type, those in the New World being dioecious, and those in the Old World being monoecious.

Description
The leaves are lanceolate in most species, and arranged in opposite pairs on the stems (alternate in one species, B. alternifolia); they range from 1–30 cm long. The flowers are produced in dense panicles 10–50 cm long; each individual flower is tubular, about 1 cm long, with the corolla divided into four spreading lobes (petals), about 3–4 mm across. Flower colour varies widely, with white, pink, red, purple, orange or yellow flowers produced by different species and cultivars; they are rich in nectar and often strongly scented. The fruit is a small capsule about 1 cm long and 1–2 mm diameter, containing numerous small seeds; in a few species (previously classified in the separate genus Nicodemia) the capsule is soft and fleshy, forming a berry.

Growing Conditions
Well-drained soils in sun.

Uses
Several species are popular garden plants, The species are commonly known as Butterfly Bush due to their attractiveness to butterflies; they are also attractive to bees, and the species with red flowers, to hummingbirds.

The most popular cultivated species is Buddleja davidiifrom central China, named after the French naturalist Père Armand David. Other common garden species include Buddleja globosa from southern Chile, grown for its strongly honey-scented orange globular flower-heads, and Buddleja alternifolia with lilac coloured flowers. Several interspecific hybrids can also be found, including B. x weyeriana (B. globosa x B. davidii).

Some species are commonly found as escapees from the garden. B. davidii in particular is a great coloniser of dry open ground; in towns in Britain, it often self-sows on waste ground, where it grows into a dense thicket, and it is listed as an invasive species in many areas. It is frequently seen beside railway lines and on derelict factory sites, although it is not able to survive the harsh winters of northern continental climates, being killed by temperatures below about -15 °C to -20 °C.

Maintenance
For hardy shrub species, pollard or coppice in early spring, as the wood is weak and splitting frequently occurs under the weight of the flowers.

Propagation
By seed or cuttings, may self-seed freely.

Pests and diseases
../Scales/ ../Bugs/ ../Beetles/ ../Caterpillars/ ../Mites/
 * Oleander scale: ../Aspidiotus nerii/
 * Brown Marmorated Stink Bug ../Halyomorpha halys/
 * Japanese beetle: ../Popillia japonica/
 * Checker spot butterfly: ../Euphydryas chalcedone/
 * Genista caterpillar: ../Uresiphita reversalis/
 * Twospotted Spider Mite: ../Tetranychus urticae/