Plant of the Week: Quaking aspen

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 300 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.

By now, most of our deciduous trees on the High Line have lost their foliage. Our iconic birches found in the Gansevoort Woodland are just one example of such trees. But one native tree still retains its leaves further up the High Line at 30th Street. It is the most widely distributed tree in North America with sightings in Canada and central Mexico. Its glossy green leaves turn a brilliant golden yellow in autumn. Populus tremuloides, or quaking aspen, are famous for their orb-shaped leaves which seem to tremble gracefully in the breeze. Populus tremuloides accomplish this feat of appearing to tremble by the flattening of its leaf petiole. By having a flexible petiole connection between the leaf and branch, aspens can literally move with the wind. The aerodynamics of the leaf are a simple but important adaptation to environments with heavy winds and snow.

Although you'd likely think its name was a descriptive term for its leaf shaking ability, this specific epithet actually comes from its liking to the European aspen, Populus tremula. Populus tremuloides are tall, fast growing dioecious trees with relatively shallow but extensive root systems. Its bark is smooth and marked by black bud scars. Populus tremuloides prefer to propagate asexually by shooting underground stems known as rhizomes from a parent tree. New stems will emerge that are genetically identical to the parent and clonal colonies.

The largest of these clonal colonies is located in Utah and has its own nickname, Pando. Pando is a single clone with 47,000 individual stems connected by a vast underground root system. Covering over 100 acres and weighing some 6,000 tons makes Populus tremuloides one of the oldest, largest and heaviest single organisms on the planet.

In addition to creating unique clonal communities, Populus tremuloides can hybridize naturally with other members of the Populus genus. It can be almost impossible to tell the difference between the young saplings coming up in a garden. Since the High Line was originally colonized by plant communities after its abandonment in the 1980's, new plant species and naturalistic habitats have formed. Only time will tell if the High Line will get its own small clonal community of Populus tremuloides.

PLANTING TIP
Plant Populus tremuloides with a shrub layer of serviceberries, fothergilla and witch hazel then add an herbaceous layer of carex, large leaf asters and golden rods.

WHERE TO SEE THIS PLANT
30th Street between 10th and 11th Avenue

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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