Vancouver has been celebrating its Cherry Blossom Festival for some time now. This year, 2011, Vancouver's Bi-centannial, it starts March 26 and ends Aprill 22. The first buds are out much earlier than that. Usually by the 2nd week in March, they are exploding.
Vancouver has over 20 different kinds of Cherry Blossom trees that bloom at various intervals, all in the early spring. I am guessing that most of these trees are from the orient. Here's a good guide to identifying species and finding good spots to shoot.
This year I will be flying over some of these areas, taking aerial photographs and making panoramas of the cherry blossoms. If you know of a beautiful area with cherry blossoms, let me know.