Clethra Hummingbird ShrubsClethra Hummingbird Shrubs for Sale Online Clethra alnifolia 'Hummingbird' (Summersweet) is a pollinator shrub that produces a plethora of white flowers for several months in mid to late summer when little else is blooming. It stands apart from the other Clethra Summersweets in that its blooms are especially compact and fragrant, attracting butterflies and hummingbirds. The glossy round leaves turn an outstanding harvest gold in the fall. They need