Hydrangeas are among the most beloved of all garden shrubs. From the jewel-like blues of the bigleaf hydrangeas to the bold foliage and incredible fall color of our native oakleaf hydrangea and the vigorous but occasionally reticent to flower climbing hydrangea, these plants add color and drama to our landscapes.
The genus Hydrangea ranges from South and Central America up to North America and is found in its greatest diversity in southeast Asia. The wide range of habitats and the overlapping of specie's ranges in Asia has led to much confusion and disagreement among taxonomists of the opposing lumping or splitting camps. Various authorities cite as many as 75 species while other recognize only about 25. Hydrangeas continue to grow happily in the landscape, apparently oblivious to the turmoil they have inadvertently caused.
The first hydrangea grown in Europe and the species which was first named Hydrangea was our own native H. arborescens in 1739. The first Asian species were not officially described until much later although they had been cultivated for many years in Chinese and Japanese landscapes. The South American species were first known as Cornidia but later moved to the genus Hydrangea. These southern hemisphere species are less well known than many of the N. American and Asian species but make lovely evergreen vines and shrubs in warm climates.
While the bigleaf hydrangea (H. macrophylla) is the undisputed king of the hill among hydrangeas, another popular Asian species is the panicled hydrangea (H. paniculata).
This species is an old-fashioned, large shrub, notable among the hydrangeas for its tolerance and even appreciation of sunny spots. It flowers on new growth making it amenable to a haircut in winter or early spring which will give it time to produce flowers in mid-summer. There have been many selections of this plant which is not only among the most heat tolerant and floriferous but also perhaps the cold hardiest surviving even the tundra-like conditions of USDA zone 4. One of our favorites is the very dwarf form called 'Dharuma' which was brought to the United States from Japan in 1989. It is sometimes confused with 'Darlido', a Dutch selection of different parentage. 'Dharuma' has been one of the few plants that has stayed smaller than we were originally led to believe, generally growing to only about 3' tall. The foliage on this selection is attractive glossy green, nicer than many other panicled hydrangeas and the flowers are held in somewhat flattened panicles as opposed to the typical cone shape of the species. Some hydrangeaphiles have suggested a bit of hanky-panky may have occurred in its past, perhaps with H. heteromalla, a typically very large species itself. The flowers on 'Dharuma' emerge early and turn from pristine white to rosy pink. The leathery foliage makes it much more deer resistant than bigleaf hydrangeas. We've been very impressed with this selection and think it has a place in most any garden.
JCRA members interested in procuring 'Dharuma' for their own gardens are in luck. This outstanding garden plant is available through our second annual member's only pre-order plant sale along with 54 other very special plants, including a few hydrangeas.