For the first 18 years of my gardening career, I lived in Milwaukee, Wisconsin. For you non-Midwesterners, that’s Zone 5A territory, which in horticultural parlance translates into short, hot summers and long, cold winters. Very long, very cold winters. So cold, in fact, that most broad-leaved evergreens. like holly and rhododendrons, won’t survive there. Thus, it wasn’t until a vacation trip to Washington DC with my mother at age ten that I first experienced one of the most common all broad-leafs, the boxwood. I remember the day quite clearly. It was a blistering afternoon at Mt. Vernon. The gravel crunched wearily underfoot, and the entire landscape seemed to sag under the August sun. Having finished the non-air conditioned house tour, we fled to the garden for relief. There, I got my first glimpse of those crisp lines of green that happily defied the heat, neatly edging the pathways with prim and proper dips and bows that somehow seemed the essence of what a traditional landscape should be. I was immediately entranced by this graceful plant, and remain so to this day, having rarely failed to include at least one member of this delightful clan in the gardens I design, even if only in pots.
I’m certainly not alone in this admiration for boxwood. Common box (Buxus sempervirens) has been in Western gardens so long that there is considerable doubt as to the species’ ancestral home. Surely the boxwood is native to central Europe. But precisely where remains a mystery, thanks largely to the Romans, who actively spread the species throughout the Mediterranean basin and beyond, completely obscuring its source. Their interest in the shrub was wholly motivated by the boxwood’s uncanny ability to be sheared into elaborate topiaries, one of the standard features of classical landscapes. Thus, for over four hundred years, wherever a Roman garden was to be found, there too was found the boxwood. With the fall of the Empire and the collapse of ornamental gardening, the cultivation of box slipped into desuetude. But the plucky little shrub wasn’t at all fazed: it simply abandoned its formal surroundings for the pleasures of the countryside. By the Middle Ages, it was to be found growing wild all over Europe in numerous forms: from foot-high dwarf cultivars to towering giants over 25 feet tall.
The boxwood’s resurgence in Western gardens is owed almost entirely to the smallest member of the family – the one I first met at Mt Vernon, – Buxus sempervirens ‘Suffruticosa’. Somewhere in 16th century this little plant was found to be absolutely ideal for edging, perfect for forming the elaborate knots and patterns that were then the height of gardening fashion. Topiary, too, returned to Western gardens about this time, and the larger box varieties were once again pressed into service with incredible zeal. William Cobbett, author of The English Gardener, echoed the popular sentiment that “If there be a more neat and beautiful thing in the world [than box], all I can say is that I never saw such a thing.” So popular was boxwood, in fact, that it became the dominant feature in many landscapes, with the ensuing backlash such horticultural monopolies inevitably inspire. Complaining that the gardens of the day were “stuffed too thick with box” many landscape designers of the late 18th and early 19th century ruthlessly ripped out centuries old box gardens, to be replaced with more “modern” shrubs and flowers. Once again the durable boxwood simply shrugged off these changes in garden fashion with the horticultural equivalent of “we’ll just see about that” – the wise old shrub knowing full well that it was far too useful to be banished for very long. Sure enough, by the early 20th century, boxwood had made a triumphant return to European gardening scene, where it remains extremely popular to this day.
In contrast to overseas, here in America boxwood was never subject to such vagaries of fashion, and has remained a beloved element in our gardens since its arrival early in the colonial period. Later, as the first Europeans moved west, the boxwood moved right along with them. One of the reasons behind boxwood’s remarkable ubiquity is its ability to root readily from cuttings: snippets placed in damp sand and kept moist will firmly anchor themselves in a month or so. This meant that tiny little pots of box could be shipped by barge, boat and even covered wagon across a largely road-less county, and that boxwood gardens were often growing and established before the second wave of settlers reached their new home.
Thanks to its ability to be shaped, box is one of the very best shrubs for adding structure and geometry to the landscape. This quality is particularly valuable in winter, when most of the garden is an amorphous mass. In sharp contrast to this laxity, the verdant boxwood stands sentinel over the white, winter landscape, maintaining form and order until finally relieved by the shrubs of spring. Nor does boxwood possess only winter appeal. On warm summer days when sunlight heats the oils in the leaves, the common box emits an extremely distinctive odor. Those who dislike the smell describe it as “musky”; for me, this wonderful fragrance seems to define “traditional,” as if the air exuded by boxwood is somehow older than the common stuff. Oliver Wendell Holmes shared my sentiments: “it is one of the odors that carries us out of time into the abysses of the unbeginning past: if ever we lived on another ball of stone than this, it must be that there was box growing on it.”
In terms of culture, box is largely untroubled by pests, though leafminers, mites and a small greenish jumping insect called the boxwood psyllid are occasional problems; each can be controlled by organic and inorganic means. Box prefers full sun, though will grow willingly in part shade, and is generally tolerant of most soils. As mentioned earlier, hardiness is more of an issue – only to Zone 5B – and boxwood can be very susceptible to snow damage unless heavy falls are knocked off the shrub before breakage occurs. Fortunately, however, breeders have recently introduced a large number of box cultivars that are far more winter hardy than their parents – the mounding form of B. ‘Vardar Valley’ being one of my very favorites. Several, like ‘Northern Find,’ ‘Ingliss,’ ‘Northland’ have withstood temperatures in the -20 – -30 degree range, making them viable into Zone 4. For gardeners in the South, an enhanced palette of golden and variegated forms is also available.