Only the trees themselves know when the seasonal blooms begin. The peak varies every year, starting as early as mid-March (1990) and as late as mid-April (1958). Hedge your bets and plan for around the first of April. It's also the time for the annual Cherry Blossom Festival
(March 28-April 12). For dates and times for National Park Service ranger-led tours addressing the historical and cultural influences of these trees in D.C., call (202) 426-6841.