23rd August 2016
The butterfly bush, or Buddleja davidii, is a plant often faced with a reputation as a thug and a wasteland weed. It sows itself and spreads like wildfire, upon derelict land and along railway tracks up and down the country. People are fearful of its ability to grow from seemingly nothing, up from cracks in paving and from the mortar around brick work. Despite its ability to conquer vast areas, the buddleia is not native – it was introduced from China in the 1890s.
Left unmanaged, it grows quickly into a towering woody monster; why then should I proclaim its worthy qualities? I’ve always liked it, imagining how dull train journeys would be in summer without its purple flowering haze. Like most plants, if given attention, the buddleia can be garden-worthy and a beautiful addition to the border.
The key factor is that it needs seasonal winter pruning, which can be carried out from November to February. This pruning is some of the harshest to be carried out upon anything ornamental, and while some gardeners will be less rash with a hand held saw, I am not. A mature buddleia can take being cut right back each year, leaving 10 inches of the main woody stem from the ground. As soon as spring takes over from winter, the stump will sprout many shoots that will quickly become tall and arching.
If it is a young plant then the pruning should not be as brutal – but it should still be carried out, taking back the previous summer’s flowering growth by half. The reason for this pruning is because they flower best on fresh growth, so the long tassel flowers will be bigger and better. It is the flowers that are the main – and perhaps only true – draw of the plant.
On the wastelands around Stoke, the buddleias are all mongrels. Reigning supreme is the normal lilac, which is pretty enough, but some cross-pollinated jewels of royal blue and magenta are to be found too – while white ones in full bloom remind me of white peacocks displaying with their tail feathers fanned out, swaying in mid-air.
I pick the flowers for events at this time of year, including our Collectors Club days. They only look good for three days at a push, but for a one-day event or party, they are brilliant crammed together en masse in a vase. Strip all the leaves from the stems as these flop, making the arrangement look ugly. Last winter, I pruned a few of the largest bushes growing across the road from the factory and along the canal to get larger flowers to pick this summer. The plants have skyrocketed with great profusion, with huge flowers dangling like bunches of grapes.
At Chatsworth, the gardeners have planted a buddleia avenue that looks especially beautiful, with plants planted in unmown grass and a path mown between them. While walking amongst these here and picking their flowers on a hot day, their honey scent fills the air. Its common name of “butterfly bush” is due to it being rich in nectar and attracting in late summer clouds of butterflies. Sadly, this year – possibly due to it being so cold at night – I am yet to see clouds of any red admirals, painted ladies or peacocks around the factory, with all these pollinators facing declines.
In the courtyard garden, I have planted the buddleia cultivar ‘Black Knight’. This one has the deepest purple flowers like a hummingbird’s breast. I’ll be keeping them in trim but am glad to have them among the cosmos for this summer and for many more to come.
23rd August 2016