What most people are thinking of when they say “Butterfly Bush” is Buddleja davidii, a species from China and Japan, cultivated in European gardens since the 1890′s. It can be invasive and in at least two states in the USA is listed as a noxious weed. There are more than 100 cultivars of this species, with recent breeding work attempting to reduce its size and make it more suitable for small modern gardens. Award of Garden Merit varieties include: B. davidii ‘Black Knight’, B. davidii ‘Blue Horizon’, B. davidii Camberwell Beauty, B. davidii ‘Dartmoor’, B. davidii ‘Darent Valley’, B. davidii Nanho Purple, B. davidii Nanho White, B. davidii ‘Royal Red’ B. davidii ‘Sunkissed’, B. davidii ‘White Profusion’, B. ‘Ellen’s Blue’, B. ‘Lochinch’, B. ‘Miss Ruby’, B. ‘Pink Delight, ‘B. ‘Silver Lilac’ and B. ‘West Hill’
Many other species of Buddleja exist however including the following awarded AGM by the Royal Horticultural Society: B. alternifolia, B. asiatica, B. fallowiana var. alba, B. globosa and B. × weyeriana ‘Sungold’.
In our garden we grow B. lindleyana, which was discovered by George Forrest on the island of Chusan and introduced to western cultivation in 1843 by Robert Fortune, who named it for the botanist John Lindley (the RHS library is also named after him). A collector in the village has a lovely yellow variety, no doubt a form of B. × weyeriana – B. davidii x B. globosa – which we are now growing ourselves. Elsewhere in village gardens, a number of cultivars in a range of colours are in full flower.
Not all Buddleja are hardy in this climate. I was recently attracted to an advertisement on EBay for B. colvilei, a stunning flower discovered by Hooker in 1849 and declared ‘the handsomest of all Himalayan shrubs’. The nursery in question was based in SW France, an area with a much kinder climate than we can offer. Tempting, all the same!