Culture
Easily grown in organically rich, medium moisture, well-drained soils in full sun to part shade. Thrives in moist soils, and appreciates a summer mulch which helps retain soil moisture. Bloom occurs on old wood. Prune if needed immediately after flowering (little pruning is usually needed). Winter damaged stems may be pruned in early spring. Plants should be given a sheltered location and winter protection (e.g., mulch, burlap wrap) in USDA Zone 5, particularly when not fully established. Plants can lose significant numbers of flower buds or die to the ground in harsh winters (temperatures below -10 degrees F), thus respectively impairing or totally destroying the bloom for the coming year.
Noteworthy Characteristics
Hydrangea quercifolia, commonly called oakleaf hydrangea, is an upright, broad-rounded, suckering, multi-stemmed, deciduous shrub that typically grows 4-6' (less frequently to 8') tall. It is native to bluffs, moist woods, ravines and stream banks from Georgia to Florida to Louisiana. It is noted for producing pyramidal panicles of white flowers in summer on exfoliating branches clad with large, 3-7 lobed, oak-like, dark green leaves.
The genus name Hydrangea comes from hydor meaning "water" and aggeion meaning "vessel", in reference to the cup-like capsular fruit.
Specific epithet is in reference to the leaves that look like those of Quercus (oak).
'Ruby Slippers’ (cross between oak leaf hydrangea cultivars 'Snow Queen' and 'Pee Wee') is a compact form that matures to only 3-4' tall and to 3-5' wide, and is noted for its compact size, large upright flower panicles, ruby red mature flowers (hence the cultivar name), mahogany red fall foliage color and exfoliating bark. Upright, elongated, conical flower panicles (to 9" long) of showy, mostly sterile, flowers begin bloom in late spring. Flowers emerge white, but quickly turn pink before finally maturing to ruby red. Distinctive, deeply-lobed, somewhat coarse, deep green, oak-like leaves (to 5” long) turn attractive shades of mahagony-red in autumn. Mature stems exfoliate to reveal a rich brown inner bark which is attractive in winter. 'Ruby Slippers' was introduced into commerce in 2010 by the U. S. National Arboretum.
Problems
No serious insect or disease problems. Some susceptibility to leaf blight and powdery mildew. Aphids and spider mites are occasional visitors.
Uses
Compact plant that is effective as a specimen or accent for foundations or other locations near homes or patios. Group or mass in shrub borders or in open woodland areas. Good informal hedge. Good for small gardens. Exfoliating mature branches provide interesting color and texture in winter. May be grown in large containers.