Mount Hamilton seems such a lofty name for the highest spot at the 446-acre U.S. National Arboretum in Northeast Washington, but the setting is hilly enough to bring fitting drama to the showy shrubs now coming into full bloom. We know them as azaleas.

For decades in mid-spring, Washingtonians have been flocking to an otherwise quiet corner of the city to view these hybrids, the work of a breeder named Benjamin Morrison. His is not a household name, and yet Morrison changed the face of the city and its older suburbs with the introduction of stout, hardy and diverse hybrids known as the Glenn Dale azaleas.

Working for the arboretum’s parent, the Department of Agriculture, he did much of his work in Glenn Dale, in Prince George’s County, and later set out some 10,000 of his hybrids on Mount Hamilton, grouped by color.

City dwellers have been taking in these azaleas since 1949, and it is as much a floral tradition here as viewing the Tidal Basin cherry blossoms.

The azaleas begin to bloom in mid-April, and the show will stretch to Memorial Day with late-season types, but the peak is this week. With no nearby Metro station, most arboretum visitors arrive by car, and traffic gets jammed on the weekends. If you can sneak away during the week, the experience would be all the more tranquil.

Many of these shrubs are now 10 to 12 feet high and match the scale of their expansive woodland location, but the visitor would do well to stop and observe the individual blooms to soak up their singular beauty and to get a sense of Morrison’s masterful eye.

Some are clear hues of lavender, white or a blue-infused red. Others have the distinctive throat patterning that seems the work of a great artist. Some solid-colored azaleas have blooms that break into stripes — Morrison, who was also the arboretum’s first director, took advantage of this quirk to breed varieties that are entirely candy-striped.

Most of the breeding records of these unnamed shrubs are missing. This helped to imperil them last year when officials at the arboretum decided to rip them out after this spring’s show, along with its boxwood collection. The arboretum was losing an annual grant of $110,000 that helped pay for the gardeners to care for them.

After a public outcry — and an anonymous $1 million donation to the Friends of the National Arboretum to endow their care — the plans were halted. But a million may not be enough. The donation might generate $50,000 a year in interest, said Jeanne Connelly, chairman of the friends group’s board. The group has calculated something else: Another $1 million in the kitty would generate an additional $50,000 per annum. Connelly and her colleagues are launching a public campaign to raise the second million. Only then, Connelly says, will the azaleas (and the boxwood) be safe.

Although azaleas are not native shrubs, the display on Mount Hamilton is entirely naturalistic. Indeed, this is how large azaleas should be viewed: not as overgrown foundation shrubs in clashing colors, but as woodland understory plants given their aesthetic and horticultural due.

It is possible to grow azaleas badly; they tend to cling on in dire circumstances. But how much better it is to see them well-sited and -grown. Here, they are pruned to produce shapely, open plants — not sheared into pink gum balls or allowed to become congested or pest-plagued. The storm damage is fixed, the accumulated leaf litter of fall is removed before it does harm, and there is little evidence of lace bug damage.

Curator Barbara Bullock, arboretum gardeners and a crew of volunteers have been working for years to keep the hybrids in good shape and the paths fixed after erosion damage. This care shows. The sense of spring engendered by these azaleas is special, and their loss would be our loss.

The arboretum’s new director, Colien Hefferan, has a hard task. The institution, part of the Agricultural Research Service, is both a public botanical garden and a research location, and she is trying to direct both roles at a time of tight and effectively shrinking government funding.

Hefferan is looking at various funding sources, including admission fees, “but we are still primarily a publicly supported institution, and we are concerned about [maintaining] access. We want people to feel as though this is a place they can come routinely,” she said. “Not just when the azaleas are at their peak.”

Do go, though, when the azaleas are at their peak.

Follow @adrian_higgins on Twitter.

If you go

The U.S. National Arboretum has two entrances, at 3501 New York Ave. NE and 24th and R streets NE. It’s open daily from
8 to 5 p.m. Admission is free. For details,
call 202-245-2726 or visit

Plus: The Friends of the National Arboretum holds its 20th annual Garden Fair and Plant Sale this weekend at the arboretum. It features the sale of new and hard-to-find perennials, shrubs and trees, along with activities for children, a sale of garden accessories and advice from arboretum horticulturists and other experts. It’s Friday 1 to 4 p.m. and Saturday 9 a.m. to
4 p.m. For details, visit