The cherry blossoms at Dumbarton Oaks are in the puffy white stage and haven't yet started opening. They're probably running a few days behind most of the trees at the Tidal Basin. But there are some other beautiful trees in bloom there, including Japanese Plum trees and Tulip Magnolias.
Part of a large, historic estate in Georgetown, the gardens of Dumbarton Oaks have a handful of large cherry trees. So if you're looking for a much less busy alternative to see cherry blossoms, it's a good option. And if you go in the next several days, the Japanese Plum trees are a highlight. The gardens as a whole are still some time away from their springtime prime, but it's a beautiful, calm oasis in the middle of DC.
In the spring the gardens are open Tuesday to Sunday from 2 to 6. More information, including entry fee rates, is available on their website.
Want to Help Support DC's Cherry Trees?
If you'd like to help support the care and upkeep of the cherry trees around the Tidal Basin, the Trust for The National Mall has launched an Endow a Cherry Tree Campaign. Donations go to the official Cherry Tree Endowment, which will give the National Park Service additional resources to fund the care, maintenance, and possible replacement of the cherry trees. You can find more information here.
The Trust is dedicated to marshaling private support for maintaining and improving the history National Mall area. I'm not affiliated with the Trust--just an admirer of their efforts.