Smooth Hydrangea, Wild Hydrangea, Sevenbark 'Grandiflora'

Hydrangea arborescens

Family: Hydrangeaceae (hy-drain-jee-AY-see-ee) (Info)
Genus: Hydrangea (hy-DRAIN-juh) (Info)
Species: arborescens (ar-bo-RES-senz) (Info)
Cultivar: Grandiflora
Additional cultivar information:(aka Hills of Snow)
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6-8 ft. (1.8-2.4 m)


8-10 ft. (2.4-3 m)


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

Sun Exposure:

Sun to Partial Shade


Unknown - Tell us

Bloom Color:

White/Near White

Bloom Time:

Mid Summer

Late Summer/Early Fall



Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:

Unknown - Tell us

Propagation Methods:

By dividing the rootball

From softwood cuttings

From semi-hardwood cuttings

Seed Collecting:

Unknown - Tell us

Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Where to Grow:

Unknown - Tell us


This plant is said to grow outdoors in the following regions:

South Amana, Iowa

Lexington, Massachusetts

Fairport, New York

Syracuse, New York

Hendersonville, Tennessee

Gardeners' Notes:


On Mar 13, 2011, RosemaryK from Lexington, MA (Zone 6a) wrote:

According to Hydrangeas: A Gardener's guide revised, by Toni Lawson-Hall and Brian Rothers, this plant was found wild in Ohio by EH Hill, AM date is 1907. The plant needs space and time to grow large. It increases by suckering to a large bush. It is criticized because its large flower heads tend to flop on their slender stems. On a large, well-developed shrub, the central flowers are held erect, while the outer ones dip more than they actually flop. Despite its name, the flower heads are not as large as 'Annabelle' but they are numerous and irregular in shape. The individual flowers are large for this species. Sepals are more pointed than those of 'Anabelle.' White blooms from July to early autumn. It is a hardy plant that withstands late frosts, and is resistant to periods of drought. Flo... read more


On Dec 9, 2004, lmelling from Ithaca, NY (Zone 5b) wrote:

In "Hydrangeas for American Gardens," by Michael A. Dirr (2004), it says that 'Grandiflora' is often referred to as the Hills of Snow Hydrangea. The corymbs are 6" to 8" across with primarily sterile white flowers; the individual "sterile" showy sepals are larger that that of 'Annabelle', but the total number of flowers in a head is fewer; the heads are not so radially symmetrical, looking like four parts loosely pushed together, and soon becoming floppy in appearance.

This cultivar, discovered growing wild in Ohio in the late 1800s, was planted througout the Midwest, East, and upper South. Plants sucker and form large colonies, 10 to 20' across.

Not as widely available as 'Annabelle', but is still reliable and a showy shrub.


On Jan 20, 2003, lupinelover from Grove City, OH (Zone 6a) wrote:

The flowers on this cultivar are so heavy that they resemble summer-blooming peonies from a distance. This shrub can grow very large, so may require pruning to keep it within bounds unless sufficient space can be provided.