Buddleja colvilei - Butterfly Bush

Buddleja colvilei, or Colvile's Buddleia, made William Jackson Hooker exclaim "the most beautiful of all the Himalayan bushes" when he discovered it in 1849. This large bush or small tree bears the largest flowers of the genus, and undoubtedly the most spectacular. They resemble those of weigelas, sporting a deep pink colour illuminated by a white throat, and are gathered in large dense and trailing terminal spikes that bloom from top to bottom of the plant. Its luxuriant foliage resembles that of the medlar or certain rhododendrons. A very beautiful species, but not very hardy, to be reserved for gardens spared by severe frost. It also grows very well in a large pot, to be stored away from frost.

Buddleja colvilei is a botanical species with large development from the Scrophulariaceae (buddlejaceae) family. It is native to the eastern Himalayas (Bhutan, India, Nepal, Sikkim), where it grows in open and sunny places, between 1600 m and 4200 m (5249.3 ft and 13779.5 ft) altitude. In nature, it can form a small tree up to 9 m to 12 m (29.5 ft to 39.4 ft) high, carried by a single trunk. In cultivation, and in our favourable climates, it will quickly reach about 4 m (13.1 ft) in all directions, depending on the nature of the soil. Often starting from a single and short trunk, the flexible branches of this buddleia are pubescent and brown-purple in colour. They bear large entire leaves, ovate and elliptical, measuring 10 cm to 25 cm (3.9 in to 9.8 in) long. They are thick and deeply veined, downy when young, glabrous when mature. Their colour is a medium to dark green. Flowering takes place in summer, from June-July to September depending on the climate, for about 3 weeks. The pink and white bell-shaped flowers are gathered in spikes 15 cm to 20 cm (5.9 in to 7.9 in) long, which form on one-year-old wood. This slightly fragrant flowering gives way to small capsules measuring 1 cm to 1.6 cm (0.4 in to 0.6 in) in diameter. This bush does not suffer from occasional drought in deep soil.

Whether planted alone or in a group, in a hedge or at the back of a perennial bed, Buddleia colvilei will make its owner proud and enhance the garden or terrace, depending on the region. Plant with other shrubs to create a stunning display. Its summer bi-coloured flowering harmonises with shades ranging from white to purple, as well as dark foliage: Physocarpus opulifolius 'Summer Wine', Cotinus coggygria 'Velvet Cloak', Sedum 'Matrona', Hibiscus acetosella, or even a purple Phormium tenax will keep it company, being careful to place them in a sunny location. You can also plant it in a tall free hedge, on the boundaries of the garden. Gardeners in colder areas can welcome it on a terrace, as it adapts well to growing in large pots.