Hydrangea are deciduous shrubs that originate from East Asia and the Americas. They are known for their large, fluffy flowerheads that range in colors from white and pink to blue and purple. Their flowerheads come a wide range of types including, domed, flat, terminal and conical. Hydrangea grow well in moist, well-drained soil and when the pH levels go above or below 6.0, the colors of the flowers change.
Smooth hydrangea (Hydrangea arborescens 'Grandiflora'), also called hills-of-the-snow hydrangea, is a deciduous shrub that is suitable to grow in USDA hardiness zones 3 to 9. It has a rounded habit and spreading, arching branches that hold the creamy white flowers. Each clustering, summer-blooming flowerhead grows 6 to 8 inches wide and blooms on the current year's wood. Smooth hydrangea grows up to 6 feet tall and has a maximum width of 6 feet. It is also a frost-tolerant variety that is ideal grown in masses to create an attractive shrub border. Smooth hydrangea grows best in full sun to part shade, preferring midday sun to full sun, and well-drained soil.
Peegee Hydrangea (Hydrangea paniculata) is a rapidly growing deciduous shrub that grows best in USDA zones 3 to 8. It has an upright, spreading form and semi-arching branches. Peegee hydrangea grows 10 to 20 feet in height and reaches a spread of 6 to 8 feet. The creamy white, summer-blooming flowers on peegee hydrangea grow on pyramidal-shaped panicles that grow 6 to 8 inches long. The whorled dark green leaves grow 3 to 6 inches long and cast a yellow tinge in fall. Peegee hydrangea is a hardy variety of hydrangea that tolerates clay soil and is drought-tolerant, making for an ideal shrub to grow in areas of limited moisture. They grow best in full sun to part shade and well-drained, moist soil.
Annabelle hydrangea (Hydrangea arborescens 'Annabelle') is a deciduous shrub that grows best in USDA zones 4 to 9. They reach a maximum height of 4 feet and have a spread of 3 to 5 feet. Annabelle hydrangea has an upright, arching form and rapid growth rate that has the shrub blooming in no time. The summer-blooming, white flattened clusters, or corymbs, grow 8 to 12 inches wide to turn green or brown when spent. The bright oval-shaped green leaves on Annabelle hydrangea grow 3 to 7 inches long. Annabelle requires full sun to part shade and moist, well-drained soil to thrive. They do not tolerate drought.