A Gardening Journal
Today in the Garden of a Lifetime: Gold-leaved Sweetgum
- Published: May 31 2016
This Spring, I've realized just how prevalent in my garden are plants that pair gold foliage with raspberry detailing. But when the gold is so bright it's actually yellow, is another color needed amidst the surrounding shades of green?
This is the full-wattage foliage of Liquidambar styraciflua 'Naree'. Its emerging stems, petioles, and leaves are all bright yellow; only slowly do they relax into chartreuse during high Summer. The five points of the palmate leaves are strikingly textural in themselves, especially when the color contrast with the surrounding plants is strong.
I've planted three of these trees in a tight row—spaced just four feet apart—alternating with clumps of a large yellow daisy, Silphium dentatum. Its bright yellow flowers can compete with any other golden hue, and its dense, solid-green foliage is a good backdrop for both its July-into-August flowers and the Spring-to Fall Naree foliage.
As these small starter trees grow, I'll keep them pruned into an informal block of growth above the Silphium flowers—say, from six to twelve feet high. Seen from ninety degrees, this pollarded Naree trio will form a bright warm-season backdrop to the ascending spheres of growth of the Poncirus trifoliata topiary, while in back of them all will be the dark green wall of a fully-formed hedge of yew.
With so much green Taxus taking shape at the back, and bright green Poncirus foliage at the front, maybe some day I can let go of the green-leaved clumps of Silphium in the middle in favor of clumps of Brit Marie Crawford ligularia. Its shiny burgundy leaves are as big as those of water lilies, and it forms colonies the size and density of mid-sized hostas. True, its late-season daisy flowers are orange, not yellow. Would they clash with the foliage of Naree? If so, I'd happily cut all the stems for a bouquet.
Or, perhaps I can keep the Silphium and bring in some blue: a large-flowered Group B or C clematis, perhaps, which I'd train up a pole into the Naree's collective canopy. Because the trees would get pruned back in late Winter (they'd mature to thirty feet otherwise), the clematis would need to be big enough to warrant being cut back in the process, while also able to flower on the new growth the pruning would encourage.
Hence, Groups B or C. Group A clematis are pruned, if at all, after their Spring flowering; it would be hell to fish stems out of the Naree canopy. Flowers of Group B or C are formed on the current season's growth—flowers of Group B can be formed on stems formed the previous season, too—so pruning the Naree branches would, in effect, also prune the clematis stems. Clematis viticella 'Perle d'Azur' (which is Group C) seems big enough, and its light blue flowers would be a good complement for the foliage of Naree, which is softer hued by August.
It will take four or five years for the full ensemble—yew hedge, Naree pollard, burgundy or blue accent, and topiary of hardy orange—to amass. But what pictures! Stay tuned.
Here's how to grow Liquidambar styraciflua 'Golden Treasure', whose green foliage is edged with a wide, irregular, and oh-so-showy border of butter yellow. Its culture and hardiness are the same but, being an extremely slow-growing shrub, it will rarely if ever need pruning.