Native Shrub: Physocarpus Opulifolius ‘Diablo’

Purple Ninebark Goes To The Dark Side

Physocarpus opulifolius ‘Diablo’, sometimes called ‘Monlo’ and ‘Diabolo’ (Oh, those plant namers love to have fun with us!) creates a bit of drama in the landscape.

This is a large shrub, but has many assets, including all season interest, attracts wildlife, provides foliage interest, and is extremely easy care.

Native over a wide range of North America

The Look

blossoms on my Diablo ninebark

Grown mainly for its dusky purple leaf, the ‘Diablo’ also boasts of spring flowers, similar in look to Bridal Spirea, winter bark interest, and a very tough nature.

The leaves are shaped most like a small hedge maple’s, although officially the description is “oval with three to five lobes”. The small flower balls are composed of tiny individual florets with five petals.

Mine blooms at the end of May or in the first week of June.

Large dense shrub with strong arching branches. The berries are small and not very noticeable against the dark leaves, but that doesn’t matter since the birds strip them early on.

Diablo Ninebark In My Garden

Though native to areas along streams and watersides, it tolerates my rather dry late summer conditions very well; I never have to water it.

The most beautiful associations with it happen to be the Euphorbia polychroma ‘Bonfire’ and the variegated Sedum. These two plants provide both harmonious and contrasting foliage. I also underplant it with a lavender blue flowered moss phlox for spring color, which I like very much, but isn’t the most outstanding companion for it (a little mundane).

Rosy pink and corals are what look outstanding against the purple maroon foliage. Any dahlia of that color, tulips, or even zinnias or petunias, make a lovely picture.

Here it is in the Garden Driveway border with Daylily and the short lived Coreopsis ‘Limerock Dream’ -the middle shrub is a ‘Tom Thumb’ contoneaster.

How to Trim a Ninebark Bush

While they have an overall graceful vase shape, they sometimes can be a bit unruly with a branch or two that sticks out like Alfalfa’s cowlick

The Rascal

For that reason you will likely need to prune them to the shape you like.

I take out older branches, especially those which have died back, remove the occasional green mutation, and reduce the general size, both top and sides each year.

The natural look I prefer demands that each branch is removed separately. The old or dead ones as close to the ground as I can cut them. the top and sides, cutting back into the bush, at a nodeWhere the lateral twigs branch off.

Pruning right after flowering (in spring) preserves the bloom for the following year.

If your shrub is older and has too much to prune, it is one of those bushes that can be cut back to six to nine inches from the ground to renew. It is a method known as “coppicing”. I have had to use this method with lilacs and Lonicera fragrantissima at times. They grow back.

There are some who coppice the bush regularly for fresh growth and to keep the size in bounds. I think that unnecessarily increases work and makes an artificial look which I dislike. But thought I would mention it for those inclined to include Diablo in their borders, etc.

Can be propagated from cuttings or seed, but colored varieties and specific traits (like dwarf size) would be most successful from either cuttings or purchased plants.

Other Ninebarks with purple to reddish foliage available for gardens:

• ‘Lady in Red’ or Ruby Spice
• ‘Summer Wine‘
• ‘Tiny Wine’ , a dwarf selection
• ‘Burgundy Candy’
• ‘Coppertina‘

If you like the qualities of the Physocarpus opuifolius bush, there are also golden leaf named varieties. I attempted to grow one, but I think I situated it poorly, although I will say that, generally, golden leaf types of any shrub tend to grow less vigorously and sometimes even poorly. The final judgment on those I will have to leave to someone else…for me this particular cultivar has been dependable, good looking, and increased with beauty each year.

I’m quite happy with it and think most gardeners with sufficient space would be, too.

Links:
Native range map and info from USDA.gov