I’m a big fan of Physocarpus, ninebark as they’re known in North America from the way the bark repeatedly rolls back off the maturing stems. Though why it isn’t eightbark or tenbark I really don’t know.
These are hardy as rocks, deciduous shrubs grown for their colourful foliage, their clusters of white flowers, their autumn leaf colour and, to a lesser extent, their berries.
The first to come to our attention in modern times were ‘Diablo’, with dark purple leaves, and ‘Dart’s Gold’, with bright yellow foliage – both useful shrubs. But it was when these two were crossed together to create what is known as Coppertina in North America and Diablo D’Or in Europe (its raiser’s name is ‘Mindia’) that I really started to take notice.
I was sent trial plants of this by Proven Winners, the American plant marketing company, now expanding into Europe, and year after year it was a star in my Pennsylvania garden for its foliage that opens in amber yellow and matures through orange to purple-bronze.
More recently I planted some that I didn’t know so well on my trial garden in Northamptonshire - thanks to John and Maria Jones of Hyfryd Plants in Wales for help with sourcing plants - and it’s time for a report.
But before that, I just want to mention physocarpus for cutting. America’s Association of Specialty Cut Flower Growers has twice voted a physocarpus as its Cut Flower of the Year. And although it can be good to cut branches lined with flower clusters, Firebrand (below) looks ideal for that use, of those I’ve tried Midnight (top) is the best and holds its leaves well as they turn.
I find fruiting unpredictable and tough to assess because those that carry the most flowers are the ones whose flowering sprays are cut for the house. The quality of autumn leaf colour, too, seems unpredictable.
New physocarpus varieties are still being released. Two dozen are listed in the current RHS Plant Finder and we’re awaiting the results of the trial of thirty varieties at the RHS Garden at Wisley that ended in 2019. In the meantime, here are my thoughts on my own mini-trial.
All Red (‘Minalco’)
I was especially looking forward to seeing All Red mature as it was touted as being smaller, more bushy, more compact and with red-bronze foliage that was noticeably smaller than that of other varieties. That’s all true - except that after a couple of years it started to produce a succession tall, very vigorous, large-leafed shoots , with internodes more than twice as long as on All Red itself. They emerged low on the plant and would have taken over completely had I not cut them out. This one is going on the compost. Now rarely seen, rightly. Bred by Pépinières Minier in France.
The foliage is coppery orange in the shoot tips, maturing to dusky purple bronze with green undersides. The flower clusters, spread across 30-40cm of stem, are relatively small, but produced on short stems at every node creating a very attractive look. Pink buds open to pink-tinted white flowers, it retains more pink colouring in its flowers than others I’m growing. Bred by John and Maria Jones of Hyfryd Plants in Wales.
Lady in Red (‘Tuilad’)
Reddish copper young shoots mature to dusky greenish purple foliage, the small clusters of pink buds fade to white as the flowers open. This is similar to Coppertina, which is said to be mildew resistant although I’ve not had powdery mildew on any of mine. This can stay in its up-against-the-east-facing-fence site until I’m desperate for space, but if I were planting now I think I’d pick Coppertina. From Jonathan Tuite of Westacre Gardens in Norfolk.
Midnight (‘Jonight’) (above)
If you’re looking for the darkest foliage colour, this is the one. The leaves open in deep purple-bronze foliage with a noticeable gloss, maturing to dull bronze - almost black- and greenish bronze on the back. The vigorous growth is ideal for cutting and lasts exceptionally well. Not selected for its flowers, so the show is sparse but the rosy pink buds open to white flowers. Another from John and Maria .
Summer Moon (‘Tuimon’) (below)
More spreading in growth than my other varieties, the chartreuse-bronze new growth matures to green with pale veins and hints of bronze creating on overall blend of green and bronze tints. The flower clusters are larger than those on any of the others, and on longer stems, with the pink buds opening to white and with noticeably red anthers. Makes an effective flowering shrub, wider than high. Another from Jonathan Tuite.
Check out my previous posts about growing physocarpus in Pennsylvania.
New plants on trial: Top Shrub – Physocarpus Coppertina (2007)
Two fine Physocarpus (Ninebarks to American readers) (2009)