Culture
Grow in average, medium to wet, well-drained soil in full sun to part shade. Prefers part shade and consistently moist, humusy, slightly acidic soils. Should be grown in locations protected from harsh winter winds in Zone 5 where it may not be reliably winter hardy throughout.
Noteworthy Characteristics
Clethra barbinervis, commonly called Japanese clethra, is a large, upright, deciduous shrub or small tree which typically grows 10-20' tall and features horizontally drooping, terminal racemes (4-6" long) of pleasantly fragrant white flowers which bloom in mid to late summer and serrated, glossy, dark green leaves which turn bright yellow (sometimes red) in autumn. Flowers are very attractive to butterflies and bees. Flower spikes give way to spikes of dark brown seed capsules which persist into winter and provide continuing interest. One of the most striking features of this shrub is the polished, grayish-brown bark which may exhibit exfoliation. Flower spikes are more horizontal and drooping and less fragrant than those of Clethra alnifolia.
Genus name comes from the Greek klethra the name for alder of which the leaves resemble.
Specific epithet means with veins barbed or bearded.
'Takeda Nishiki' was first found by Takeda Hisayoshi and his son on Shiko Island, Japan. It is an upright shrub or small tree with highly variegated leaves that are splashed with pink, green and white in spring, mature to green and white in summer and acquire red to gold tones in fall. It has pendulous clusters of lightly fragrant white flowers in summer that age to ornamental dark brown seed capsules that persist into winter. Mature plants have polished tri-colored bark. It grows 10 to 20 ft. tall and 10 to 15 ft. wide. ‘Takeda Nishiki’ may be sold as FIRST SNOW®.
Problems
No serious insect or disease problems.
Uses
Japanese clethra is an excellent, trouble-free shrub or small tree which makes an excellent specimen or small grouping for conspicuous locations in lawns, shrub borders or woodland gardens where its attractive foliage, fragrant summer bloom, good fall color and interesting winter appearance (bark and persistent seed spikes) can be showcased. Also a good shrub for moist areas along streams or on the periphery of ponds or water gardens.