Plant of the Week: Pennsylvania sedge

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.

Spring ephemerals aren't the only plants gracing the High Line with their blooms these days. Practice patience and close observation and you'll notice the subtle flowers of Carex pensylvanica beneath the shady areas of our woodland edges. The minute inflorescence of this species is rich brown and spike-like, but the pale yellow anthers of the male flowers are more likely to catch your attention.

The native range of Carex pensylvanica is Eastern and Central North America- parts of Canada to Mississippi and Georgia. Many sources state that it prefers an environment of part to full shade and mostly dry soil. However, our gardeners have found C. pensylvanica to be remarkably versatile and able to survive in a wider range of conditions- for example, full sun and moist soil. It has a low growing habit and spreads by rhizomes, making C. pensylvanica an effective ground cover. Slow to spread, but once established, it is commendably hardy. Its low creeping habit and fine textured leaves make it an effective lawn replacement for the shady space. In my experience observing C. pensylvanica in the wild areas northwest of New York City, its growth habit resembles a winding river weaving its way through the natural landscape. I imagine this scene translates well to replace a conventional lawn.

Over 1500 species of Carex exist worldwide. Commonly known as sedges, Carex are low-growing perennials that beg comparison to grasses. However, sedges are members of the Cyperaceae family, they prefer colder and wetter regions, and their stems are angular rather than round. There are four species of Carex planted in the High Line gardens, each adding a different texture and shape to the design. The diversity of this genus make it worth your time to explore.

Plant C. pensylvanica in masses to replace a conventional lawn, or weaving between other herbaceous perennials to add depth to your garden. It will flourish in most conditions, although it prefers more shady situations. Compaction due to foot traffic may inhibit the survival of this species.

Gansevoort Woodland, Chelsea Thicket, planting bed to the north and west of the 23rd Street Lawn, Philip A. & Lisa Maria Falcone Flyover, and Wildflower Field & Radial Plantings.

Photos by Ayinde Listhrop.

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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