There are well over a hundred species of Buddleia in the world. They are native to North and South America and parts of Asia and Africa. The most popular species in gardens is Buddleia davidii or the Butterfly bush. (1a;1b) The “Buddleia” part of the name refers to Adam Buddle an English botanist and cleric who lived in the 17th century. The “davidii” part refers to Fr. Armand David a French Catholic priest, biologist and missionary who worked on the Chinese mission. While he was in China, he discovered many species of flora and fauna unknown to Europeans. One of these was this Buddleia bush which he discovered in central China in 1869.
This species has become naturalised in Ireland. This means that its seeds have germinated in the wild even though it is not an indigenous plant. Naturalised Buddleias colonise derelict sites, neglected gardens and old, crumbling walls.
It is an extremely useful plant for attracting a wide range of butterflies who feast on its copious nectar supplies. Peacock, small tortoiseshells, red admirals and large whites flock to it for nectar during the summer when it is in bloom. (2a;2b;2c). The first three butterflies lay eggs on nettles and their caterpillars eat these. (3)
Usually introduced plants do not attract feeding fauna; the latter feed on indigenous flora because that flora evolved in tandem with their own evolution. However, the Buddleia is an exception because a wide variety of moth caterpillars feed on its leaves.
Buddleias bloom on new wood so the plant should be pruned in spring down to c. 30cm from the ground. To prevent overcrowding remove some of the old wood right down to the roots.