How to Prune Buddleja
Buddleja davidii and it’s cultivars will respond however hard you prune them.
I will never forget the day some years ago when as a rookie horticulturist and student of gardening, I asked my mother if I could practise my newly acquired pruning skills on a Buddleja davidii in the family garden.
On completion, I realised that my pruning was on the severe side but it was not half as severe as the look on Mum’s face when I showed her the Buddleja.
The Buddleja davidii ‘Black Knight’ had previously stood at over 6ft tall and I had just pruned it to within 8 inches of the ground! Mum was convinced that I had killed her beautiful Butterfly Bush. I asked her to trust me and sure enough within a few weeks new green shoots were sprouting from the ankle-high stump followed by a fantastic floral display in the summer of the same year.
Buddleja davidii and it’s cultivars are as tough as old boots. I am always amazed, when travelling by train to London to see Buddlja davidii growing like weeds at the track edge and in the very limited light levels of the railway tunnel entrances and exits.
Buddleja davidii is native to China and Japan. There are many cultivars of the species all with cone-shaped flower clusters of small fragrant blooms. Flower colours available include white, pink, red, lilac, purple and almost black as in the above mentioned Buddleja davidii ‘Black Knight’.
No prizes for guessing that the Butterfly Bush is very attractive to insects, especially butterflies, making it an ideal planting choice for a wildlife garden.
Foliage colour is not restricted to mid-green, Buddleja davidii ‘Harlequin’ has green and cream leaves.
For the best floral display, I prune in late February or early March. I am not quite as brave as I used to be, my method now involves cutting back to the lowest visible active young shoots. My technique has changed because I have come across some rather elderly Buddleja specimens in various gardens where I work, and I am not totally convinced that such annual severe pruning is in the best interests of these more mature plants.
If however you have a large, rather neglected Buddleja davidii to rejuvenate I would always recommend the severe pruning method. It is remarkable how the plant responds and it seems to celebrate in the summer of the same year by producing a much improved floral display.
So, however hard you choose to prune your Buddleja davidii this spring I defy you to kill it, however low you go!