Diana Hibiscus ( Althea ) - Rose Of Sharon Hibiscus syriacus 'diana' 'Diana' is a sterile triploid that produces very few if any seed pods. Triangular, lobed, leathery, dark green leaves (to 3.5" long). A Royal Horticutural Society of Great Britain Award of Garden Merit plant. It features ruffled, thick-petaled, clear white single 4 Inch flowers. Hibiscus syriacus, commonly called rose of Sharon or shrub althea, is a vigorous, upright, vase-shaped, multi-stemmed, deciduous shrub. It may be trained as a small tree or espalier. Showy, hollyhock-like, 5-petaled flowers appear over a long, early-summer to fall bloom period. Each flower has a prominent and showy center staminal column. Height :5-8 Feet Width : 4-6 Feet Exposure : Full sun Hardiness Zones : 5-8