A Gardening Journal
Good Together: Golden Weeping Ash, Japanese Holly, Orange-Twigged Linden
- Published: October 22 2016
Plant a plant, begin an experiment. Does the plant establish? Does it look good as it matures? Do you keep up with the maintenance it needs, and are you and the plant both screwed when you don't? Ultimately, does the plant do what you thought it would? Either way, do you still like it or do you say "What was I thinking?" Is the experiment ever over, or does it morph into new ones?
When I planted the orange-twigged lindens that I've since trained into a long espalier, I flanked the main passage through it with upright Japanese hollies. I also planted a weeping gold-barked ash, thinking that someday its lax branches would cascade down like a Victorian curtain at the side of the opening.
Fifteen years into the experiment, there's still no cascade, but there is plenty of splay.
Another surprise: fall is the peak of the ash's show. Each of the three plants—the ash, the lindens, the hollies—responds differently to the increasing chill and, happily, those differences also showcase this experiment's unexpected successes.
Below (and in pouring rain), the dark-green foliage of the upright holly, Ilex crenata 'Steeds', remains this color year-round, whereas in fall the mid-green leaves of the weeping ash, Fraxinus excelsior 'Aurea Pendula', turn a yellow so bright it seems to be bleaching to white.
Color is just one of the contrasts between the two. Each small rounded holly leaf is a fraction the size of just one of the pointed leaflets of the frond-like foliage of the ash.
Further, the holly leaves are arrayed densely on slender dark-purple branches that angle upward and outward...
...while the ash leaves flounce outward and, often, downward from stems whose bark is chrome yellow.
These two plants' habits couldn't be more different. As is usual for holly, Ilex crenata 'Steeds' forms a dense and rigid mound if allowed to grow free-range; the mound formed by Steeds is taller than wide, but only just: six to eight feet tall and five to six feet wide. Because it accepts pruning readily, Steeds is easily kept more narrow, as here. And because I provide support to mine by tying their major branches to the posts of the espalier frame, growth can also extend higher than usual, to about nine feet.
At any height, the dense evergeen foliage and upright branches of Steeds make it susceptible to damage from snow and ice. Pruning to maintain a more compact shape is only partly effective, in that the pruning also creates a denser outer layer of foliage that could catch more snow and ice than growth that is looser. I tie major branches to the galvanized pipe with clothesline, as well as clip off new stems that project beyond the desired columnar profile. The result is that the shrub has better internal support and many fewer cantilevered branches upon which snow can rest.
The splayed branches of the ash provide their own contrasts with the dense, compact, and dark-green holly. In the picture below, I tied one particularly long and low ash branch diagonally through the lower portion of the Steeds holly, and another through the holly higher up.
Each has produced a sash of loose and leafy side stems. This young growth has the brightest bark and, so, makes the strongest contrast with the dark holly. Even better, the very act of tying each main branch lower than it would have angled on its own also encourages still more side stems. More growth = more contrasting stems = a bigger, brighter show.
But despite this cultivar's name, Aurea Pendula, its stems aren't so much weepy as flexible. They weep only inadvertently, as they lengthen and become so heavy that their internal structure can no longer hold them outward, let alone upright. (What a difference in habit from the branches of, say, weeping beeches. They are rigid even when young, and can stream directly downward with immovable intensity. Their trajectories aren't inadvertent at all; rather, they seem intentional and even maniacally so.)
The ever-emerging side stems from this weeping ash begin yet another experiment. If allowed to grow too long and too profusely, they will shade out the Steeds holly. They could even block the opening through the espalier. I'll need to thin some and shorten others and, perhaps, train the rest downward more vertically. Then, they will weep strongly enough to keep the opening open, and also stay sparse enough to let sun reach the holly so it can remain dense enough to hold its desired columnar shape.
The interaction of the ash and the linden is more subtle. Lindens are favored for espaliers, in part, because their branches are also really flexible. Even stems an inch thick can usually be reoriented as needed, then tied in place. So the juxtaposition of ash and linden can't create interest that would depend solely upon differences in branching habits.
Spring into fall, at least, it's the differences in foliage that are strong: leaves of the linden are heart-shaped (cordate is the technical term), and those of the ash are feathery (pinnate is the term). Although foliage of this Aurea Pendula cultivar is softly yellow for a bit in spring, by summer the foliage is green and, so, can contrast with that of the lindens only through shape and texture. By mid-fall, the ash foliage has become the brightest of its growing season while the linden foliage is still wearing its summer green. For a couple of weeks, then, the difference in colors makes this foliar contrast terrific.
By winter, foliage of both the ash and the linden will have fallen. Then the exposed yellow bark of young linden stems provides only modest contrast to the grey-brown bark of the mature linden branches. But the cold-weather performance of these lindens' young twigs confirms their cultivar name, Winter Orange. And handily, training the lindens into an espalier is also the way to encourage the emergence of more young side stems in the minimum of space. I'll report back in winter on how well these trees and I have been able to collaborate on creating a lively display of yellow and orange twigs. Yet another experiment, then, is very much ongoing.
What will happen at the top of the espalier? Stems that are supported can usually extend farther than when growing free-range; branches of the ash have already reached the top of the espalier, where I've tied a couple of them horizontally. This encourages growth of their side stems, and three of the resultant five that have (so far) emerged are shown below. They are erupting straight up, without even a hint of the weeping or at least sprawling tendency they'll assume when heavier, longer, and more mature.
I'll allow a few of these "eruptors" to grow freely year after year and, so, be able—finally!—to witness the timeline for branches of this weeping tree to do just that. I could also tie other eruptors partially down in hopes they'll arch over sooner. Yet again, another experiment has begun.
How big—both high and wide—would this top growth want to become as it grows on its own? What length and orientation of any particular branch would be pleasing in contrast to the growth of espaliered linden below? Fifteen years ago, I had assumed that a so-called weeping ash would do just that: cascade down from the top of the espalier like a curtain. Now it's more clear that, while Fraxinus excelsior 'Aurea Pendula' will easily form diagonal sashes and outpouchings of growth on the side of the espalier, growth atop it seems more likely to be mounding, widely projecting, and umbrella-shaped.
Nowhere, then, will my original goal of an outright cascade of ash be realized. Instead, growth that is sashing, outpouching, and umbrella-ing will be this tree's future. Formation of each of these three types of growth is proving to be a separate experiment. How will the results look in combination with the wall of espaliered lindens and columns of Japanese holly? A trifecta of inspiration, dedication, and endurance I hope but, even after fifteen years in, it's still too soon to tell.
Here are all the articles on another golden European ash, Fraxinus excelsior 'Aureafolia'. Its branches are upright, not lax and wide-spreading, but its foliage, bark, hardiness, and cultural needs are similar. Aurea Pendula is equally susceptible to a number of fatal pests and diseases; see the "Downsides" box in the "How to grow it" table in this one of the articles.
Here are all the articles on another upright cultivar of Japanese holly, Ilex crenata 'Sky Pencil'. It is strikingly narrow; in comparison, Steeds is merely less broad and mounding. Both forms need some support to maintain their ideal upright profiles; Steeds needs pruning, too. Their hardiness and cultural requirements are similar.
Here are all the articles on orange-twigged linden.