The Dumbarton Oaks Gardens will be closed for significant renovations starting this July. They will remain closed until the following March.
In a letter to the public, the organization explains:
The time has now come to undertake large-scale improvements to the garden’s water supply network, which dates to the garden’s original creation in the 1930’s. We are therefore obliged to close the gardens to the public from July 10, 2017 to March 15, 2018.
This is a bummer for residents and visitors. But the silver lining is that the gardens will be open for this spring’s fireworks. And they will be reopen by the following spring.