Culture
Winter hardy to USDA Zones 5 to 8. Easily grown in average, medium moisture, well-drained soils in full sun to part shade. 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. This shrub may be cut to the ground (also immediately after flowering) if it becomes scraggly, unkempt or otherwise in need of rejuvenation.
Noteworthy Characteristics
Philadelphus × lemoinei, commonly known as mock-orange, is a hybrid deciduous shrub in the Saxifrage family that typically grows to 4-6’ tall with an upright arching habit. Hybrid cultivars in the Lemoinei group are generally noted for having small fragrant flowers (to 1” or more wide) and sparsely toothed leaves (to 2 1/2” long).
In 1883-84, Victor Lemoine (1823-1912), plant breeder in Nancy, France, crossed Philadelphus microphyllus (U.S. native) with Philadelphus coronaries (southern Europe/Caucasus native) to produce the hybrid shrub known today as Philadelphus × lemoinei. Pointed, narrow-oval, medium to dark green leaves (to 2” long) are smooth above but hairy below. Fragrant, white-petaled flowers (to 1 1/2” diameter) bloom in 3 to 7 flowered terminal racemes in late spring to early summer.
‘Silver Showers’ (‘Silberregen’) is a German hybrid cultivar in the Lemoinei group which typically grows to 3-4’ tall with a spread to 4-5’ wide. It features large, flat-faced, fragrant white flowers in loose racemes which bloom in early summer, most often singly on rounded shrubs.
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 is in obvious reference to Victor Lemoine.
Common name of mock-orange is in reference to the sweetly fragrant flowers which generally resemble the scent of orange blossoms.
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, hedges, shrub borders, low screens or open woodland areas.