Clethra barbinervis

Japanese clethra is a dense, deciduous, oval-shaped flowering shrub in the Clethraceae family native Japan. It is typically found in open mountain forests and disturbed woodland areas. The genus comes from the Greek klethra for alder, which this plant's leaves resemble. The species means with veins barbed or bearded.

The shrub matures to 9 feet high by 9 feet wide, although specimens can reach 20 feet. This plant prefers partial shade in moist, lime-free, organically rich, acidic, and well-drained soil but will tolerate full sun. Summer cuttings can be easily rooted and it will spread through suckering to form colonies. Protect new spring growth from later spring frosts.

Japanese Clethra produces dropping, fragrant white flowers on the current season's growth in summer into early fall. Glossy, dark green leaves turn bright yellow to red in autumn for good fall color. Dark brown seed capsules persist into winter and the polished, grayish-brown bark exfoliates. Flower spikes are more horizontal and drooping and less fragrant than those of native summersweet.

This plant has gained the Royal Horticultural Society's Award of Garden Merit

This shrub will add 4 seasons of interest to the garden. Plant it along ponds or streams, in small groups or as a specimen.

Diseases, Insect Pests, and Other Plant Problems:  No significant problems. Spider mites can be a problem in hot, dry sites.