Plant of the Week: Rose mallow

The spectacular foliage on the High Line this autumn is a testament to the unseasonably warm weather we've been enjoying in New York City. As the winter weather picks up, the garden is slowly starting to shed its layers and reveal its bones. The gardeners work hard to keep the dormant plants looking as beautiful as possible during the long, cold winters. One of Piet Oudolf's phrases that we keep in mind while tending the fall and winter garden is "Brown is a color too." Rose mallow, with its vertical structure and distinctive seed capsules, is a stand-out brown plant.

Photo by Timothy Schenck

The seed capsules of rose mallow persist throughout winter, providing a delightful detail that stands out against the expansive winter skies. It's hard to imagine that just three months ago these brown pods were giant pink flowers swaying in the wind. With flowers that are quite large and borne at the top of the plant, it is recommended to plant rose mallow among other supportive wetland plants such as cattails and reeds to keep it upright as long as possible. Not only does this provide a much needed scaffold, but it lends a naturalistic effect that is evocative of the High Line.

Photo by Joan Garvin
Hibiscus moscheutos ssp. palustris is unique in that it maintains a graceful effect despite its large, sturdy growth habit. Rose mallow starts growing later in the season, but quickly reaches six feet tall. The six-inch, saucer-shaped pink flowers have finely striated petals that appear slightly ruffled and delicate. Although each flower only lasts 1-2 days, new flowers open in rapid succession providing blooms through mid-summer to early fall. The downy, dark-green leaves vary in shape, but are most commonly deltoid and range from 3-8 inches long. The herbaceous stems are so rough and thick that they almost seem woody.

Photo by Maeve Turner.

This native wetland perennial was first collected in 1680 by the English plant hunter Rev. John Banister and was in cultivation as early as 1700. The subspecies name, "palustris," is Latin for "swampy" or "marshy." In Victorian times, giving a hibiscus meant that the giver was acknowledging the receiver's delicate beauty. Native Americans have also used the plant for treating inflamed bladders. The rose mallow has also developed specialized entomological associations including the rose mallow bee for pollination and the hibiscus seed beetle that eats the seeds.

PLANTING TIP:

Rose mallow requires full sun and a moisture-retentive, rich soil. In zones 5-10 it can be treated as perennial, overwintering easily with good drainage and the root crown protected with a layer of mulch. You may want to stake the plant to keep it upright until the stems have stiffened a bit. If using seeds, soak for 24 hours before planting. This plant spreads through rhizomes and seeds and can create large stands if given the space.

WHERE TO FIND THIS PLANT:

The Diller von-Furstenberg Sundeck at West 15th Street.

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. Every week we share one of our gardeners' current favorites with you.

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.


TD Bank is the Presenting Green Sponsor of the High Line.

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