Nematology Circular No. 59 Botany 10)
Fla. Dept. Ag ic. & Con *I y Services
Di ision of Plant Industry
MAR 26 1987
OAK-LEAF HYDRANGEA, HYDRANGEA QUERCIF
A NATIVE SHRUB USEFUL AS AN ORNAMEN
)LIAUniversity of Florida
K. R. Langdon
INTRODUCTION: The genus Hydrangea contains about 23 species, several of
which are grown as ornamentals (1,2). Notable among these are the French or blue
hydrangea, H. macrophylla (Thunb.) Ser., grown both as a yard and a pot plant;
hills-of-snow, H. arborescens L. 'Grandflora', a white flowered shrub; and the
P. G. hydrangea, H. paniculata Siebold 'Grandiflora', white flowered large shrub
or small tree.
Hydrangea quercifolia Bartr., the oak-leaf hydrangea, is native throughout
the Southeastern United States (3,4), including much of Florida. It is a large
shrub to 6 ft (2 m) tall, or sometimes in cultivation in Florida, to 10 ft (3 m)
tall and often twice as wide. The plant is easily propagated by cuttings or by
suckers or offsets from underground runners. The large clusters of white flowers
(fig. 1) produced in the early summer are quite showy and make the shrub very at-
tractive. These flowers, as they age, turn from white to pinkish to bronze, and
eventually to tan as they weather.
Fig. 1. Hydrangea quercifolia
Contribution No. 206, Bureau of Nematology, P. O. Box 1269, Gainesville, FL 32602
DESCRIPTION: Spreading shrub to 6 ft (2 m) tall; twigs densely pubescent
with reddish brown to white hairs, older twigs and branches with thin, reddish
brown bark exfoliating in shaggy strips. Leaves deciduous, opposite, blades 4-12
in. (li-30 cm) long and nearly as broad, deeply 3-7 lobed, the lobes again lobed
or serrate with sharp teeth, apex of lobes acute or acuminate, sinuses rounded to
angled, base of blade rounded to truncate, often somewhat decurrent onto petiole,
upper surface dull green, nearly glabrous, lower surface paler, densely wooly,
petiole 1/2-1/5 as long as blade, denselywooly with white to reddish brown hairs.
Flowers May-June in large terminal showy panicle 4-12 in. (10-30 cm) long, rachis
stout, pubescent, penduncles erect or ascending, 2-4 in. (5-10 cm), pendicels
slender 1/16-1/8 in. (2-4 mm), flowers of 2 types, small fertile and large, showy
sterile flowers, sterile flowers on outer part of inflorescence, rays 4, petal-
like, 1/2-1 1/2 in. (13-40 mm), orbicular to obovate, at first white turning red-
dish or purplish, fertile flowers with 5 petals, 1-2 mm long, oblong, greenish
white, stamens 8-10, excerted, filaments filiform, ovary inferior, 2-4 celled,
stigmas 2, sessile, divergent, ovules numerous (1,2,3,4).
USES AND CULTURE: Uses for oak-leaf hydrangea include specimen plants where
space is adequate, or as an untrimmed hedge or background where screening is de-
sired. Plants become too large for foundation plantings, but in other situations
where some restriction of size is important, plants can be cut back considerably
in the fall. Even with such trimming they become rather large.
The oak-leaf hydrangea grows best in moist, fertile, light, well drained
soil (4). It, however, will tolerate soils ranging from moderately dry, well
drained sand to moist, heavy clay loam soil with adequate surface drainage. It
grows well in light shade, but flowers best in full sun. In Florida it is adapted
best to central and northern parts of the state.
1. Bailey, L. H. 1929. The standard cyclopedia of horticulture.
Macmillan, New York. 3 vol.
2. Bailey, L. H., Hortorium. 1976. Hortus third. Macmillan,
New York. 1290p.
3. Small, J. K. 1933. Manual of the southeastern flora. Univ.
of North Carolina Press, Chapel Hill. 1554p.
4. Vines, R. A. 1960. Trees, shrubs and woody vines of the south-
west. Univ. of Texas Press, Austin. 1104p.