Common Name: smooth hydrangea
Type: Deciduous shrub
Zone: 3 to 9
Height: 3.00 to 5.00 feet
Spread: 4.00 to 6.00 feet
Bloom Time: June to September
Bloom Description: White
Sun: Part shade
Suggested Use: Rain Garden
Flower: Showy, Good Cut, Good Dried
Tolerate: Rabbit, Erosion, Clay Soil, Dry Soil, Wet Soil, Shallow-Rocky Soil
Easily grown in average, medium, well-drained soil in part shade. Tolerates full sun only if grown with constant moisture. Intolerant of drought, with foliage tending to decline considerably in dryish conditions. This species blooms on new wood, and may be pruned back close to the ground in late winter each year to revitalize and to encourage vigorous stem growth and best form. Plants may die to the ground in harsh winters. If not pruned back, any weakened and/or damaged stems should be removed in early spring.
'Annabelle' is a smooth hydrangea cultivar which features much larger flowers than the species. It is a deciduous shrub with a rounded habit which typically grows 3-5' tall. Clusters of sterile, white flowers appear in huge, symmetrical, rounded heads (corymbs) which typically grow 8-12" across. Blooms in June for up to two months, sometimes with a small repeat bloom in the fall. Dark green, serrate leaves (3-8" long). Species (Hydrangea arborescens) is native to southern Missouri. 'Annabelle' is a naturally occurring cultivar which was discovered in the wild near Anna, Illinois.
No serious insect or disease problems. Many species of hydrangea, including this one, are susceptible to bud blight, bacterial wilt, leaf spot and mildew, however this cultivar seems to have excellent resistance to these diseases. Although 'Annabelle' stems are erect and generally considered to be stronger than those of the species, the heaviness of the flower heads, particularly when moistened by rain, can cause the heads to droop to the ground and thus require staking. Pruning stems back to the ground in late winter each year helps promote stem vigor.
Mass in a part shade area of the mixed shrub border for long-lasting and often spectacular summer bloom.