hard pruning

All buddleias respond well by growing from really old wood if the shrub is cut back hard.  So said George E. Brown, one time Assistant Curator at Kew, in his classic The Pruning of Trees, Shrubs and Conifers, first published in 1972.  It has been revised and updated since by Tony Kirkham, another Kew man, so let us hope the advice has not changed, since today I took a saw and cut back the Buddleia x weyeriana 'Golden Glow' in the meadow very hard indeed.

B. x weyeriana forms are hybrids of B. davidii, the familiar butterfly bush you see alongside railway lines and sprouting out of the upper portions of neglected buildings, and B. globosa, a less commonly seen species from Chile, which bears round (the clue's in the name) balls of orange flowers greatly loved by bees.  Hybrids between the two typically have flowers intermediate between the long, pointed clusters of B. davidii and the round ones of B. globosa, which may be yellow, purple, or a mixture, produced over a longish season with an element of repeat flowering inherited from the Chilean parent.  They are attractive, easy going plants, but after more than a decade and several years of total neglect, my specimen had a lot of dead wood in it.  I removed that, and then took a long, hard look at the tall, gaunt, bare-at-the-base shrub, and decided that I would rather have the flowers lower down where I could see them properly.  Plus, it had got out of scale with a neighbouring tulip tree, which is doing its best and does not deserve to be loomed over by a buddleia.

After the fell deed I fed it with blood, fish and bone, to help keep it going until I have time to tackle that bed properly, which may not be for months.  George E. Brown also says that buddleias are strong growers and require feeding and mulching, and my poor B. x weyeriana hasn't had any of that for years.  I hope it survives the experience, and grows away lustily, but if it doesn't then a replacement would not be desperately expensive, and should grow away fast.  I have seen for myself the amazing regenerative powers of B. davidii, since replacing a 'Black Knight' that had blown clean out of the ground in an especially bad gale only for the original plant to regrow from the remaining roots, so that I now have two.

What I don't know is whether, if 'Golden Glow' survives, I can expect any flowers this year.  B. davidii flowers on the current year's growth, hence we routinely prune them in late winter for flowers in the late summer, whereas B. globosa flowers from strong growths made the previous year, according to Brown, and hard pruning will sacrifice flowers for at least one season.  I ought to know which of its parents B. x weyeriana takes after, but am ashamed that I have not observed it that closely, having never pruned it.  I think I'm in luck though, since its Wikipedia entry (which I didn't read before giving it the chop) says it will grow to two metres if pruned hard annually, which implies that you can and still get the flowers, small panicles comprising globose heads of pale yellow flowers flushed with lilac.  And it turns out that 'Golden Glow' was one of the first two hybrids named, raised by a Major van der Weyer during the Great War and given the RHS Award of Garden Merit as long ago as 1923.