A Gardening Journal
Today in the Garden of a Lifetime: The White-leaved Willow
- Published: October 20 2015
Can there ever be too many plants with silvery foliage, especially in the Fall, when so much other foliage turns red, orange, and yellow? Plants with silvery foliage rarely reveal another color in Fall—and so, like the "white" willow here, they show up all the more. As seen from a second-story window, much of the garden is a surf of billowing growth that my gaze merely skims over as I focus on distant garden trees and surrounding native woods.
Perhaps two hundred feet away is the startling silvery mass of one of my pollarded white willows.
Leaves of Salix alba 'Sericea' are actually green, but each bears a coat of short, close-lying white hairs that reflect so much of the comparatively bright light of the sun that they appear to be nearly white. When photographed in the lower-intensity light of indoors, the difference is striking. While the bottoms of the leaves are still white, the upper surfaces are clearly green, with just a sheen of silver.
Even at closer range, the silver of the upper leaf surface is still not distinguishable as hairs, let alone individual ones.
And yet, the upper surface of the foliage is as much as part of the overall look of the tree—especially from a distance, and from the higher vantage of my long shots, above—than the lower. As shown in the interior shots, there is plenty of green light reflected from the upper surface and, yet, from any distance, the white light reflected by what is just the barest covering of short hairs dominates. Happily for the visuals with which this tree graces any outdoor garden, our eyes are blinded by the white.
Because there isn't room in my garden beds for full-size trees—and also because I love to prune and train woody plants—each of my pair of white willows is pollarded. This happens in early Spring, just as new foliage is breaking. (In my experience, pollarding white willows in mid-Winter can be fatal.) Because new stems formed as a result of pollarding can grow ten feet and longer in a season, the look right after pruning is shocking. What had been a dense rounded tree is now, seemingly, a telephone pole. But countless new stems emerge from the length of the trunk; within a month, they are over a foot long, and by the start of Summer, three feet and longer.
Although the foliage of pollarded plants is often enhanced as a result of the pruning (think of the gigantic leaves of a pollarded Paulownia, or the more brilliantly colored leaves of a pollarded Cotinus), foliage of Salix alba 'Sericea' seems just as exciting on free-range growth as on pollarded. The goal of such radical pruning, then, is drastic size control.
Here's how noisy this tree was one September when it was, mysteriously but beneficially, aswarm with insects.
Here's how to grow a sister cultivar of this remarkably colorful willow.