Common Name: rose of Sharon
Type: Deciduous shrub
Family: Malvaceae
Zone: 5 to 8
Height: 5.00 to 8.00 feet
Spread: 4.00 to 7.00 feet
Bloom Time: July to October
Bloom Description: Lavender with dark red eye
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Hedge
Flower: Showy
Attracts: Butterflies
Tolerate: Deer, Drought, Clay Soil, Black Walnut
Culture
Easily grown in average, medium moisture, well-drained soils in full sun to part shade. Best flowering occurs in full sun. Prefers moist, organically rich soils, but tolerates poor soils and some drought. Very tolerant of summer heat and humidity. Generally tolerant of urban conditions. Prune to shape in spring. Pruning back to 2-3 buds in late winter may produce larger blooms. Easily propagated by stem cuttings. May be grown from seed, but seedlings may not have the exact same flower color as the parent. Species plants can self-seed aggressively in optimum growing conditions.
Noteworthy Characteristics
Hibiscus syriacus, commonly called rose of Sharon or shrub althea, is a vigorous, upright, vase-shaped, multi-stemmed, deciduous shrub that typically grows 8-12’ tall. It may be trained as a small tree or espalier. Showy, hollyhock-like, 5-petaled flowers (to 3” diameter) appear over a long, early-summer to fall bloom period. Each flower has a prominent and showy center staminal column. Palmately-veined, coarsely-toothed, three-lobed, medium green leaves (to 4” long) are attractive during the growing season but produce no fall color.
Genus name is the old Greek and Latin name for mallow.
Specific epithet suggests the plant comes from Syria which appears to be false because it is native to eastern Asia.
'Minerva' is an introduction of the U.S. National Arboretum in Washington, D.C. It has lavender flowers (4-5" diameter) with dark red eye spots. This cultivar is a mostly sterile triploid that produces very few if any viable seed pods.
Problems
Some susceptibility to leaf spots, blights, rusts and canker. Japanese beetles, whiteflies and aphids are occasional insect visitors. Japanese beetles can severely damage foliage if left unchecked.
Uses
Excellent flowering shrub that may be massed, planted in groups or used as a specimen. Good for foundations and shrub borders. Also can be effective as a hedge or screen.