by May Wang
Each summer, the eight hundred or so bushes in the Rose Garden erupt in a wash of color, designed by Beatrix Farrand and Mildred Bliss to deepen in hue from north to south. The prim boxwoods and straight, hardscaped paths give a sense of order and formality that perhaps belies the year-round care and expertise the gardeners invest to encourage showy and repeated blooms throughout the summer and to keep rose diseases and pests at bay.
Gardener Kim Frietze has spent much of the past four years in the Rose Garden trying out new plantings—while remaining faithful to Farrand and Bliss’s original vision—and techniques to maintain the room’s formal but somewhat naturalistic character. Pruning the bushes and removing spent blooms is a continual task that starts in late winter after the last major frost with a “hard cut.” “The flowers bloom on new wood during the current growing season,” Frietze explains, “so you cut the roses back hard during dormancy to encourage fresh canes to grow.”
Older bushes, like the Mr. Lincoln variety in the southeastern corner that likely dates from the renovation in the 1990s eventually produce few, if any, new canes, so they are cut higher up. But for the fast-growing younger bushes, the hard cut is also an opportunity for some structural pruning. “Because of the aggressive way roses grow,” says Frietze, “the bush might strangle itself,” so she also prunes out any canes that might grow over one another as the season progresses.
After the first cut in late winter, it’s mostly a waiting game until the blooms—the first flush—emerge in late spring. In the Rose Garden, the arrival of the blooms is also a good time to assess how new plantings fit in with existing bushes and if they adhere to Farrand and Bliss’s design intent. The “Madame Anisette” variety was being tried out on the northern side of the main walkway that worked with the color gradient, but it grew aggressively and without many blooms. It was replaced with a different planting this year, though that was also removed because the emerging leaves presented with the rose mosaic virus.
Due to the unfortunate loss of a white oak just outside of the Rose Garden, a previously shaded space opened up along the southern wall, where a new David Austin variety, “Queen of Sweden,” is now planted. The color—a delicate pink—matches the reds and pinks and whites on the southern end, and the full blooms resemble the roses in the bed just across the walkway, “Maman Cochet,” which is a favorite of Rigo Castellon, longtime crew leader of the section of the gardens that includes the Rose Garden. “I looked for varieties for Rigo to select from that most resemble ‘Maman Cochet’ that he would enjoy spending time with,” says Frietze.
After each flush throughout the growing season, gardeners prune off the spent flowers (called “deadheading”) and remove rosehips to encourage the plant into another round of blooms. In early fall around October, the bushes are allowed to produce rosehips, which are the fruit of the flowers that emerge in the absence of deadheading. “The different varieties have differently colored rosehips,” Frietze explains. “Hip production signals the rose to start going dormant, so it’s nice to see the whole cycle of the rose.” After the onset of dormancy, the bushes are then leveled off to look tidy and to take off some weight in case of snowfall.
Caring for this garden room is not all sunshine and roses, however, as the gardeners are always on the lookout for diseases like rose rosette and black spot and pests like midges, which can spread rapidly in the room with few other companion plants. “Selecting disease-resistant varieties grown on their own root systems has allowed us to reduce overall inputs in the room,” says Frietze. “For the most part, we try to contain things either with biocontrols like predatory nematodes or very small amounts of spraying,” except for fungicides to treat the boxwoods against boxwood blight.
Over the decades, the face of the Rose Garden has evolved as specific plantings or design features have come and gone, but the overall outline and aesthetic effect remains unchanged. “There’s not much you can daydream about in the Rose Garden because it’s so defined,” reflects Frietze. But beyond the individual rosebushes, the room is masterfully designed to have a certain formality but also a lightness and openness—the retaining wall on the western side is cleverly concealed by climbing rosebush plantings from below and twining wisteria from above.
Go back in time in the Rose Garden in A Century in the Gardens online exhibit, or plan a visit to the Dumbarton Oaks Gardens.
May Wang is postgraduate writing and reporting fellow.