Buddleja davidii – a white form in the garden of the old peoples home in Chabris
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’.
Buddleja x. weyeriana variety
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.
Buddleja lindleyana at the Garden Design Academy, France
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!
A Gardener in France 
In my small garden here in Holland I also have a Buddleja davidii. I keep it in check by cutting it down to about 30 cm height every year in March. Thus preventing it from getting too big with much smaller flowers. This way the flowers it produces are admittedly fewer, but much bigger.
Hello Cybermum,
in my haste to post this edition of the blog, I neglected to say anything about pruning or anything else which would help people grow their own Buddleja.
This is my fault, and I agree that with B. davidii is best cut down hard at the beginning of the season. Having said that, I also cut it back by about half to protect it from winter damage, no doubt bringing on some damage in the process!
B. lindliana is best left alone, I find.
And I forgot to mention that I also cut it back by half to protect it from winter and more specifically from wind damage. So we were both a bit hasty. 😉