Plant of the Week: Winter Sun Mahonia

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.

As the winter months move closer, our lush green landscapes have faded into various shades of browns, yellows and reds, providing an opportunity for evergreens in our gardens to truly standout. One such favorite plant is Mahonia x media 'Winter Sun'.

The parent plant Mahonia x media, commonly known as Oregon Grape, is a cross of Mahonia japonica, native to Japan and Mahonia lomariifolia, native to China. Mahonia x media 'Winter Sun' was selected in 1966 at the Slieve Donard Nursery in Ireland for its fragrant flowers and compact habit. Mahonia species are often mistaken for Hollies due to their similar spiny serration, dark green color, and waxy appearance on the foliage. While the genus superficially resemble hollies (Ilex sp.), Mahonia officially belongs to the barberry family, Berberidaceae.

Winter Sun Mahonia can grow to 10 feet tall, but regular pruning controls its size. The 12-18 inch pinnately compound leaves consist of many long, leathery individual leaflets with sharp spines along the leaf margins. New, red-tinged leaves emerge in the spring and mature to a deep, glossy green. Beginning in late fall and continuing through winter, Winter Sun Mahonia blooms with long spikes of bright yellow flowers which provide color at the time of year when most ephemerals are finished blooming. The flowers also provide a valuable food source for over-wintering hummingbirds and late season pollinators. In spring, the plant is filled with deep blue berries that provide returning migrating birds with a source of food.

Winter Sun Mahonia grows best in U.S. Department of Agriculture Hardiness Zones 5 through 8 in part-shade/full-sun cultural conditions. In the winter, Mahonia can tolerate freezes but prefers more temperate climates that do not experience temperature extremes. In the cold marginal zones 5 and 6, keep the shrub out of direct wind to avoid winter burn and defoliation.

PLANTING TIP
This shrub thrives in well drained, organically rich soils with pH ranging from 5 to 7. In alkaline conditions, the plant won't bloom as profusely and can suffer from nutrient deficiency. Mahonia x media 'Winter Sun' requires little maintenance as it is rarely afflicted by pest and disease. Pruning can be done to control spread and to manage any dead, damaged or diseased growth. The best time to do so is right after the shrub has stopped flowering in late winter.

WHERE TO SEE THIS PLANT
Between 19th and 21st Street planting beds

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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