Best grown in organically rich, slightly acidic, medium moisture, well-drained soil in full sun to part shade. In St. Louis, Japanese pieris doesn’t seem to perform well in most locations. Summer foliage decline and reduced vigor results in weakened plants that may succumb to a harsh winter. It grows best in locations sheltered from wind with some afternoon shade. Remove spent flowers immediately after bloom.
Pieris japonica is a broadleaf evergreen shrub that typically matures to 9-12’ tall with a dense, upright habit. It features drooping clusters (racemes to 6” long) of lily-of-the-valley-like white flowers in early spring. Serrulate, oblanceolate to obovate-oblong leaves (to 3.5” long) emerge orange-bronze but mature to glossy dark green. Leaves are evergreen. Bead-like flower buds are set in late summer for the following year and provide winter interest and contrast to the evergreen foliage. Many cultivars are available featuring flowers in various shades of white, pink and deep rose.
Synonymous with and sometimes sold as Andromeda japonica.
Genus name is the name of one of the Greek Muses.
Specific epithet means of Japan.
‘Red Mill’ is a popular cultivar that is particularly noted for the fiery red color of its newly emerging foliage. Serrulate, oblanceolate to obovate-oblong leaves (to 2” long) emerge bright red in spring, then briefly transition to mahogany before maturing to dark green. Large pendulous clusters (racemes) of urn-shaped, lily-of-the-valley-like white flowers bloom in early spring (April). If spent flowers are not trimmed off after bloom, they are followed by small 5-valved capsules. Bead-like flower buds are set in late summer for the following year and provide winter interest and contrast to the evergreen foliage. 'Red Mill' typically matures in a spreading mound to 4-6' tall.
Dieback (phytophthora) and leaf spot are occasional problems. Lace bug infections can be a serious problem, particularly in the eastern U.S. Watch for mites, nematodes and scale.
This cultivar is ideal for foundations and foreground placements in the shrub border. Also effective in open woodland areas. Effective when mixed with other broadleaf evergreens. May be massed, grouped or grown as small specimens.