Plant of the Week: Japanese clethra

The High Line's planting design is inspired by the self-seeded landscape that grew up between rail tracks after the trains stopped running in the 1980s. Today, the High Line includes more than 500 species of perennials, grasses, shrubs, and trees – each chosen for their hardiness, adaptability, diversity, and seasonal variation in color and texture. Some of the species that originally grew on the High Line's rail bed are reflected in the park landscape today. This week we share one of our gardeners' current favorites with you.

Clethra barbinervis is a large deciduous shrub that is an excellent and overlooked choice in the garden. The shrub is typically celebrated for its drooping terminal racemes of late summer flowers, or its fragrant blooms, a scent so sweet some describe it as "cloying." However, the High Line gardeners are currently admiring its handsome exfoliating bark this winter. The bark varies from smooth gray to rich brown, and peels back as it matures to reveal tones of lavender and cream, or even salmon, as one High Line gardener described. Besides the attractive bark, you may also recognize this tree in winter by its hanging stalks of brown seed capsules.

"Barbinervis" refers to the bearded or hairy veins of the specimen's leaves, something you won't be able to inspect until leaves arrive in early spring. The flowers are a nectar source for wildlife, so if you want butterflies and bees in your garden, Clethra barbinervis is a good choice. The fall foliage is an attractive array of yellow, bronze, and occasionally red. If you are looking for a large shrub with four seasons on interest, Clethra barbinervis is a solid and somewhat unique option. In fact, Clethra barbinervis is the recipient of the Award of Garden Merit, an award given by the Royal Horticultural Society to help gardeners choose the best plants for their garden.

While most of the High Line's specimens grow in the understory created by gray birches, Clethra barbinervis grows in sunny areas on the tops of mountain ridges in its native temperate habitat of eastern China, Korea, and Japan. It ranges in size from a large shrub to a small tree, and its growth habit is a satisfying candelabra shape. In his five years of gardening on the High Line, the gardener who cares for our Clethra barbinervis reports having no serious pest or disease problems, an experience that aligns with the Royal Horticulture Society's perspective.

American sources report that Clethra barbinervis prefers part shade, and somewhat moist and acidic soil. Most importantly, choose a protected location to plant your Clethra barbinervis, particularly if your region experiences the harsh winter winds similar to those the High Line encounters. It is an excellent selection to add late summer interest to your garden when many other plants are past peak bloom.

Gansevoort Woodland

Our horticultural team counts on members and friends like you to help keep the High Line beautiful and thriving. Join our community of supporters who play an essential role in the High Line's most important gardening projects.

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