Rose-of-Sharon or shrub althea (Hibiscus syriacus) is a frequent denizen of old gardens where it often grows 8 to 10 ft. high and 4 to 6 ft. wide. The toughness and durability of this old-fashioned was eloquently affirmed by Felder Rushing in his 11th book, Tough Plants for Southern Gardens: “A drunk driver once ran over my great-grandmother’s old althea and it came right back with new flowering growth. That’s one tough shrub if it can be pruned with a pickup truck!”
Rose-of-Sharon blooms in the torrid months of June to early September. Depending on the cultivar, flowers can be single or double in a range of colors that include white, pink, purple, blue and red. The flowers give rise to highly fertile seed pods, which can become a nuisance. I still remember a roadside rose-of-Sharon that I rescued more than a decade ago. I never realized that this single shrub would thank me with bazillions of offspring. Fortunately, there are new, sterile to semi-sterile cultivars that have been selected for their compact nature (older cultivars are prone to legginess) and gorgeous flowers.
Despite the availability of new releases, I’m old-fashioned and like to go retro with these 1970s releases from the U. S. National Arboretum: ‘Diana’ (white), ‘Aphrodite’ (pink), ‘Helene’ (white), and ‘Minerva’ (lavender). These sterile cultivars named after Greek goddesses have compact growth habits, leathery dark green leaves, and produce little or no seeds. Site them and any rose-of-Sharon in full sun. Since they produce flowers on current season’s branches, prune these deciduous shrubs when they’re dormant in late winter, preferably with bypass pruners or loppers–not your granddaddy’s pickup.
© Bob Polomski