Culture
Easily grown in average, medium moisture, well-drained soils in full sun to light shade. Prefers moist, organically rich soils. Tolerates a wide range of soils except poorly-drained ones. Flowers appear on the prior year’s growth, so prune as needed immediately after flowering.
Noteworthy Characteristics
Philadelphus pubescens, commonly called mock orange, is a dense, upright, multi-stemmed, deciduous shrub that typically grows to 4-10' tall and as wide. It is native to open woods, wooded slopes and stream banks in the south eastern to south central U.S. from Tennessee to southern Illinois south to Arkansas and Alabama. It is grown in landscapes primarily for enjoyment of its mildly fragrant, 4-petaled, creamy white flowers (each to 2" across) with yellow stamens which cover the shrub with an abundant bloom in late spring to early summer (June - July in St. Louis). Flowers appear in small 3-9 flowered panicles. Each flower purportedly resembles the shape of an orange blossom, hence the common name of mock orange. Shrubs in the genus Philadelphus are also sometimes commonly called syringa which is both misleading and difficult to comprehend because Syringa is the genus name of lilacs. Flowers give way to seed capsules. Ovate leaves (3" long) with acuminate tips and shallow marginal teeth have pubescent undersides (hence the sometimes used additional common name of hoary mock orange for this shrub). Gray bark exfoliates with age.
Var. verrucosus (from Latin meaning warty) primarily differs from species plants by having elliptic to ovate-elliptic leaves which are acute or obtuse at the base in comparison to species plants which have ovate leaves which are rounded at the base. In the State of Missouri, var. verrucosus is only found in McDonald County in the far southwestern corner of the state. Some authorities now consider var. verrucosus to be synonymous with the species and no long give it separate recognition as a botanical variety.
Genus name comes from the Greek word philadelphus meaning loving one’s brother or sister. A Grecian and Roman family name. New York Botanical Garden suggests that the genus name instead comes from Ptolemy Philadelphus, a king of the third century B.C.
Specific epithet from Latin means hairy/downy in reference to the leaf undersides of this shrub.
Problems
No serious insect or disease problems. Some susceptibility to leaf spot, canker, powdery mildew and rust. Aphids, nematodes, scale and leaf miners are occasional visitors.
Uses
Foundation plantings, shrub borders, open woodland gardens, low screens or hedges. This shrub has minimal ornamental interest when not in flower.