pole butterflybush

Buddleja officinalis largely resembles the commoner B. davidii in shape and size, growing to less than 2.5 m in height. The inflorescences are honey-scented mauve panicles, shorter (under 8 cm) than those of davidii, and more conical. The leaves are lanceolate, under 15 cm long, softly pubescent, the upper surface rich green in colour, the underside grey. 2n = 38.

Buddleja officinalis is not fully frost hardy, unable to survive temperatures lower than −10° C, and is best grown against a south-facing wall. The shrub should be cut back hard each year immediately after flowering in spring. Propagation by softwood cuttings is easily accomplished, using vermiculite as a rooting medium. In the UK the shrub is often grown as a nectar source for vanessid butterflies such as the peacock on emergence from hibernation. Hardiness: RHS H2, USDA zones 8 – 9. One notable cultivar of B. officinalis is Buddleja 'Winter Sun'.