The Doublefile Viburnum, V. plicatum, is the showiest of the clan, lining its long, spreading branches with pure white blooms in June. 'Summer Snowflake' puts on the same display but doesn't know when to quit. It blooms continuously all summer and into fall, a feat few hardy shrubs can match. It's also relatively compact, maturing at 6-8ft tall by 8-10 wide.
With the possible exception of Rhododendron, no genus offers as many attractive and useful shrubs as this one. Viburnums prefer rich, evenly moist, slightly acid soil and generally flower most abundantly in full sun. For more information on Viburnum care, click on Growing Guide.