Oakleaf Hydrangea
 

Mature Size, Growth, Longevity

Average mature size of 4-6' tall (to 8') and wide. Branching upright multiple stems. Suckers and slowly spreads from the roots. Upright habit, but vertical stems do little side branching. May eventually spread and form a globular to mounded habit. Slow to medium growth rate. Very slow for the first few years. Classified as "very short-lived," averaging 20 years or less.

Native Range

U.S. Native — Native to southern forests in Georgia, Florida, Tennessee, Alabama, Mississippi, and Louisiana; Introduced 1803.

Flower and Fruit Details

Elegant flowers are large, white, changing to purplish-pink, on 4-12" long by 3-4" wide, erect, gently tapered panicles, delicately perfumed, June - July. Dried flowers persist into late winter. Fruits are tan or brown, 0.125", in October, with old infructesences persisting through winter into late March.

Leaf and Bark Features

Deciduous: Leaves are opposite, simple, 3-7 lobed, and "oak-like", resembling a large, red oak (Quercus rubra) leaf (thus the common and scientific names), deep green in summer. Fall color is a beautiful red, or variable orange, or reddish-purple. Color holds late into fall/early winter, often present for the first snow. Notable Bark: Bark is exfoliating, papery, red-brown to rusty-orange or salmon colored.

Culture and Care

Prefers moist, fertile, well-drained, loamy soil, but tolerates clay, plus acid or alkaline soil (6.1-8.5 pH). Very shade tolerant. Sensitive to drought, so mulch & keep roots cool. Tolerant of calcareous & limestone-rock soils. Intolerant of wet sites. Best with some shade. Zone 5-9, but some twig dieback may occur below 0°F, especially is below -10°F. Protect new plants overwinter in Zone 5. Very resistant to insects; occasional problems with powdery mildew or leaf blight which are rarely serious, frequently suffers from sun scald.

Strengths, Weaknesses, Other Facts

Once established, looks good all year because it retains its leaves with great fall color well into December. Dirr calls it, "one of the most beautiful native flowering shrubs, particularly for the handsome flowers and bold foliage." 4-season interest: Spring, Summer, Fall, Winter. Somewhat difficult to use in landscapes due to early slow establishment and overall coarseness (stout, upright stems but very few side branches). Deer will eat this plant. Makes a good cut flower.

Suggested Uses

A great plant for mass plantings, the shrub border, or in shady locations.

Taxa and Plants of this Species at BCA