Culture
Best grown in organically rich, medium moisture, well-drained soils in full sun to part shade. Can be trained as a small single trunk tree, but is best grown as a large, multi-stemmed shrub. May display best shrub form if regularly pruned to a height of 6-10’ tall. This is one of the most winter hardy of the hydrangeas. It thrives in urban conditions. Bloom occurs on current season’s growth, so prune as needed in late winter to early spring.
Larger flower panicles can be obtained by thinning the plants to 5-10 primary shoots. In full bloom, the weight of the flower panicles will typically cause the branches to arch downward.
Noteworthy Characteristics
Hydrangea paniculata, commonly called panicle hydrangea, is a vigorous, upright, rapid-growing, somewhat coarsely textured, deciduous shrub that is native to China and Japan. It typically grows to 8-15’ (less frequently to 25’) tall, and features oval to ovate dark green leaves and upright, sharply-pointed, conical, terminal flower panicles (to 6-8” long) containing both fertile and sterile flowers (mostly non-showy fertile flowers) that bloom from mid-summer into fall.
The genus name Hydrangea comes from hydor meaning "water" and aggeion meaning "vessel", in reference to the cup-like capsular fruit.
The specific epithet paniculata refers to the arrangement of the flowers in panicles.
‘Renhy’, commonly sold under the trade name of VANILLA STRAWBERRY, typically grows to 6-8’ tall and to 4-5’ wide. Foliage habit is upright in early summer changing to cascading as summer progresses due to the added weight from the flower panicles. Panicles (7” by 5”) are primarily composed of showy sterile flowers which bloom on new growth from mid-summer to fall. Flowers open white, change to pink and finally mature to pinkish-red, with multicolored flowering (vanilla white to strawberry red) occurring in late summer as new flowering stems emerge to join mature flowers. Strawberry red flower color is typically retained for 3-4 weeks prior to flowers turning brown. ‘Rehny’ resulted from a controlled breeding program commenced in 1987 in Gorron, France, in which H. paniculata ‘Unique’ was self-pollinated for the purpose of obtaining a selection of hydrangea that bloomed in early season with red sterile flowers. U.S. Plant Patent PP20,670 was issued on January 26, 2010.
Problems
Some susceptibility to bud blight, bacterial wilt, leaf spot, rust and mildew. Aphids and mites are occasional visitors.
Uses
Mass or group in a mixed shrub border or open woodland garden. Also effective as a lawn specimen, accent or hedge. Provides late summer bloom when few other shrubs are in flower.