Often used along fence lines or as hedges, shrubs are bushy, woody plants that may vary widely in shape and size. There are many white-flowering shrubs, including rhododendron, which also includes azaleas and mountain laurel. When selecting a shrub with white flowers, it is important to consider when you want the shrub to bloom, how big it will become and what it will be planted with. Since many shrubs are evergreen, they can compliment a home landscape even when they are not flowering.
Found all over the South, azalea falls under the genus rhododendron, and is an evergreen or deciduous shrub, depending on the climate. Azaleas thrive in acidic soil, prefer filtered shade and require moist soil. Some varieties are hardy to minus 25 degrees F, but all require more humidity than rhododendron.
Many varieties have white blooms, including cultivars of the sweet azalea (R. arborescens), the late-blooming swamp azalea (R. viscosum) and the Texas azalea (R. oblongfolium). There are also many hybrids, which may be more disease tolerant and have longer bloom periods, that produce white blooms.
Hydrangea (Hydrangea) are deciduous shrubs or vines that are known for their large, round flower clusters. Hundreds of tiny star-shaped flowers bloom in clusters above vibrant, green foliage, usually during summer. Hydrangeas are hardy in nearly every climate, though they should be planted in full sun in cool climates and part shade in hot climates. Depending on the variety, hydrangeas may range in size from 3 to 15 feet.
The 'Annabelle' cultivar of the smooth hydrangea (H. arborescens) produces a 12-inch-wide white bloom, and the Peegee hydrangea (H. paniculata) produces white flower clusters up to 15 inches wide that age to pink.
One of the largest plant genuses, rhododendron (Rhododendron) has more 10,000 named varieties, though most plants have long, narrow, fuzzy green leaves and produce a profusion of blooms in summer. Rhododendron require acidic, moist soil and filtered shade to thrive.
The "Belle Heller" cultivar produces a pure white bloom with a gold spot and is hardy to minus 10 degrees; the "Fragrantissimum" cultivar produces fragrant, funnel-shaped white blooms and is hardy to 20 degrees; and the "Snow Lady" cultivar produces a fragrant white bloom with a black stamen and is hardy to 0 degrees.