Landscape Rehab at Dumbarton Oaks Park

By Carol Cavanaugh,


Winds howl outside my house on a Saturday morning in the dead of winter. So why am I heading outdoors to spend my day? Am I nuts? Well, it’s pretty hard to find something to write about gardening in February, but I have a deadline to meet. So this intrepid columnist is headed to Dumbarton Oaks Park, where a group of volunteers is gathering to remove invasive plants from a bowl-shaped area along Lovers Lane. And I have discovered that my cashmere-lined leather gloves WILL fit under my longest gardening gloves. As we begin, the area resembles a movie setting for a planet overgrown with massive vines. Dumbarton Oaks Park Conservancy is working with Rock Creek Park to remove the invasives in order to restore the native woodland.

Just blocks from our houses, a massive project is underway, aimed at restoring the landscape to the original vision of its designer, landscape architect Beatrix Farrand (1872–1959). While Dumbarton Oaks itself was planted with formal gardens, the 27-acre area behind it was meant to be a distinct "wild garden." Designed in the 1920s and 1930s by Farrand, this less-formal garden moved from private to public land in the 1940s and was left on its own beginning in the 1950s. You don’t need to be a master gardener to realize that a garden left for 60 years will get overgrown with invasive plants.

In 2010, the Dumbarton Oaks Park Conservancy was established to restore the gardens to Farrand’s original design intent. But what was that? Farrand’s plans for the wild gardens had been lost. As Liza Gilbert, ASLA, chairwoman of the Conservancy’s Signature Committee writes plaintively, "How does one restore and rehabilitate a landscape without the plan of the original designer?" Gilbert says that Farrand believed "topography must dictate design. She was a master at reading curves, the sculptural quality of the land, and using plants to highlight those features."


What we do know about Dumbarton Oaks Park is that Farrand designed five meadows, drawing the visitor from one to the next. Now, the Conservancy has partnered with Rock Creek Park to restore the gardens. To oversee the effort, they have engaged Larry Weaner, considered to be the nation’s foremost expert on meadow design and restoration. As invasive plants have been removed with thousands of hours of volunteer labor, Farrand’s design has begun to reappear in key places.

The first two meadows have been carefully seeded with a mixture of grasses. Eventually, the Conservancy wants warm-season grasses to take over. Warm-season grasses, which are native, support the local ecosystem, providing little pockets for bees and insects to live, which in turn draw birds looking for rest stops as they journey. The bad news about warm-season grasses is that, as perennials, they can take up to 7 years to flower and produce seed. So these grasses have been planted within a protective layer of cooler-season grasses. Through mowing in spring, cooler-season grasses will be allowed to seed less and less, as the warmer-season grasses become established and eventually take over. Meanwhile, if the invasive plants are controlled enough that they can no longer set seed, they can be held at bay.

If you’re as intrigued by this project as I am, you can get more information at If you’re looking for a place to take out your aggressive tendencies, join a team of volunteers and tear out invasives on the second and fourth Saturdays of each month. Or you could donate some money, or get involved in other ways. This looks like good stuff, folks.