One of the loveliest, but remarkably underused, natives of the late spring/early summer is our native Mock Orange, Philadelphus lewisii. The state flower of Idaho, it was discovered by Merriweather Lewis and gets its common name from the delicious orangey scent that makes it attractive to bees and humans alike.
Flowering for several weeks starting in late May or early June, the tall, arching branches are covered with a multitude of snow-white blossoms of usually four petals, bright yellow in the center. After the petals fall, the sepals remain in a way that looks like a second, different type of flower, providing some longer seasonal interest.
The oval leaves start out in the spring as a soft green and turn yellow in the fall. Note: during May and June the gloriousness of P. lewisii can be seen (and smelled) in Portland at Oaks Bottom Wildlife Refuge, SE 7th & Sellwood Blvd.
P. lewisii is tolerant of a wide variety of conditions, from full sun to partial shade, from moist to dry. It can survive well on available rainfall here in the valley and is known to be quite drought tolerant, though sometimes a little additional water can help it to thrive and flower more vigorously.
P. lewisii makes a good garden candidate for both its startling beauty and fragrance but because of its attractiveness to bees, it isn’t the best candidate for placement near a door . Its height and arching branches make a good backdrop for other plants, adding a sense of structure and stature to the garden.
P. lewisii photo courtesy of Las Pilitas Nursery
Regular light pruning will help keep your Philadelphus filled out and denser; plant a few together to provide your garden with a sweet –smelling summer privacy hedge. In any case, it is beneficial to occasionally do a rejuvenating pruning (see side bar) to keep it at its best.
Philadelphus lewisii 'Blizzard'
P. lewisii, ‘Blizzard’ This is a cultivar of the species that was discovered and cultivated in western Canada. Its appeal is a smaller size (4-5’ rather than the often 6’+ of the straight species), greater hardiness (down as low as zone 2-3) and even more abundant flowering than the species (hence the name!)
P. lewisii 'Blizzard' photo provided courtesy of Photo provided by Cornell Plantations
Common name: Mock Orange
Characteristics: Deciduous, multi-stemmed shrub with long, arching branches. Grows 4-6 ft., sometimes taller, with an abundance of richly-fragrant pure white blossoms in the late spring/early summer. After the petals fall, the sepals remain looking like small flowers of a different sort. Leaves have a soft yellow fall color.
Culture: Prefers full to partial sun. Is adaptable to a variety of soils and conditions and can be quite drought tolerant, though some supplemental water may help it perform more successfully, depending on the season’s weather.
Pruning: Benefits from some regular pruning, usually just to shape, and this light pruning will help keep the plant more dense and full; every few years it is beneficial to cut to the ground about a quarter of the oldest branches, to open up and freshen the plant and allow for maximum bloom (in a similar way that is recommended with hydrangeas).