I’ve been known to turn up my nose to spireas. My parents had old-fashioned Vanhoutte spireas (Spiraea × vanhouttei) lining their driveway, and several years back, when I helped with garden renovations, I recommended popping them out. Vanhouttes can grow more than eight feet high (unless aggressively pruned), and the plants were too large for the spot—fountains of fine twigs spilling well beyond the brim. We tucked a few transplants into the back of a larger perennial bed, but the others were simply removed and discarded. The bumald spirea (S. japonica), likewise, is part of the trio of oft-overused landscape plants that seemingly, for a period, appeared side-by-side in every new foundation planting, alongside lipstick-colored gobs of Knock Out® roses (Rosa ‘Radrazz’) and wheat-like columns of Karl Foerster grass (Calamagrostis × acutiflora ‘Karl Foerster’).
Those standbys have their place, of course, yet discretion is recommended. There are, nevertheless, good spireas—even spectacular spireas. One that has caught my attention recently is the steeplebush (Spiraea tomentosa, accession 129-2005*A), which is currently a flash of color on the edge of Dawson Pond. The flowers are produced in narrow clusters that top the branches like flamingo-pink flares in a backyard firework show. The stems, likewise, are trim and upright, about three-feet high, and copper-colored on close inspection. In this location, nestled within a group of marsh mallows (Hibiscus moscheutos ssp. palustris, accession 1475-83), the plant looks well behaved—a single, shapely clump, providing attractive contrast from the broad leaves of the mallow. In its native habitat, however, the plant can wander, sometimes forming dense, suckering stands in moist meadows in the northeastern United States and southeastern Canada.
The steeplebush, compared to the Vanhoutte spirea, is not a common landscape plant, but I could imagine a change of fortune, especially for use in a mixed perennial planting, like those designed by Piet Oudolf—the Dutch designer, famous for bringing swaths of perennials to the High Line, in New York, and Lurie Gardens, in Chicago. Steeplebush is the kind of plant that doesn’t want to emcee the garden entertainment, but it serves as a game and talented member of the cast—taking a moment in the spotlight in late summer, when other members are cooling off backstage. The Vanhoutte, on the other hand, is the kind of shrub that engulfs the front porches of older houses—a dramatic show of white flowers in early spring, which declines into a mess of foliage for the remainder of the summer, like a star actor who doesn’t know when to leave the stage.
Preferences, of course, are personal, but they also suggest something about the waves of gardening fashion. When longtime Arboretum horticulturist Donald Wyman wrote about spireas in 1961, he had less-than-fond things to say about the steeplebush: “a weedy, three foot high shrub with poor foliage, possibly looking well in old cow pastures where it is native but suited for little else than in naturalistic plantings.” Conversely, he noted the “gracefully arching habit” of the Vanhouttes, which, he mused “is difficult to improve upon, especially when the branches are covered with flowers.” If we fastforward a couple of decades, however, horticulturist Michael Dirr describes spraying leftover herbicide on Vanhoutte spireas when he moved into a new house, concluding that “there are many better species.” What is it, I wonder, that drives these changes in mood and fashion? Dirr doesn’t provide a full-throated endorsement of the steeplebush, however, writing that it is “reasonably attractive in a late summer sort of way.” On this front, I’ll take the mantle—and perhaps I’ll even convince my parents to add a few.