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Tuesday, February 12, 2013

Plants with Winter Interest Part 12 - River Birch


River Birch in MG Karen Strimple's Landscape
About a year ago, Master Gardener Jill Hudock wrote about an elegant tree with beautiful exfoliating bark that added a textural component to her winter landscape – the Paperbark Maple, or Acer griseum. She also noted, however, that the tree can be a little pricey, as well as a bit finicky to grow.

River Birch in MG Karen Strimple's Landscape
Here is another tree with exfoliating bark that also adds texture to the winter landscape, but is native to North America,  and is easy to grow, readily available, and comparatively inexpensive – River Birch, or Betula nigra. The genus name Betula is latin for “pitch”, which etymologists (word researchers) guess came from bitumen, a tarry substance that can be distilled from the bark of birch trees, and nigra translates as "black", referring to the mature bark color of the species.

River Birch in MG Karen Strimple's Landscape
River birch is a fast-growing, medium-sized, deciduous tree, hardy in zones 4-9, which occurs naturally on floodplains, or alluvial soils near rivers, and in marshes, or wetlands.

River Birch in MG Karen Strimple's Landscape
In the home landscape, it can be trained to form a single trunk or allowed to follow its natural tendency toward a multi-trunked tree. It is native to North America with a primary range in the southeastern quarter of the United States from eastern Texas and southeastern Iowa to Virginia and northern Florida. We’re at the northern end of its natural range here in Franklin County, although it is widely cultivated in home landscapes and public parks, and there are scattered natural populations found along rivers and streams as far north as southern Minnesota, central Wisconsin, and the middle New England States.

River Birch in MG Karen Strimple's Landscape
Height at maturity comes in at 40-60 feet. The tree is monoecious, meaning it forms separate male and female flowers on the same tree. Male flowers (catkins) are formed on twig tips in the fall and mature the following April or May. Female catkins appear with the leaves and open in early spring. The fruit matures in late spring or early summer, and is dispersed when it ripens. In their native habitat, River Birch seeds are a food source for a number of species of birds including ruffed grouse and wild turkey. Native Americans used the boiled sap as a sweetener similar to maple syrup, and the inner bark as a survival food.

River Birch in MG Karen Strimple's Landscape
The outstanding ornamental value of River Birch in the home landscape is the exfoliating, or peeling bark that provides the winter interest we’re looking for in this series. The bark color can vary from a dark gray-brown to pinkish-brown, or cinnamon colored, to a creamy, pinkish white, depending on the cultivar, peeling away in curly, papery sheets. Prince Maximilian of Austria, who later became the short-lived emperor of Mexico, called it the most beautiful of American trees when he toured here in the mid 19th century.


River Birch in MG Karen Strimple's Landscape
Master Gardener Karen Strimple has always been a fan of the tree, and when she and her husband moved to Blue Ridge Summit from the Washington DC area, their property offered the perfect spot – a site in the front yard with a perched water table that required landscape specimens that can tolerate wet feet, or soggy conditions that take some time to drain, especially in the early spring after snow melt. She’ll never forget the day the first tree was planted. It was September 11, 2001. Another tree was planted a few years later. Karen loves the “see throughness” of the tree in summer, with foliage that flutters appealingly in the breeze. A neighbor, with an older specimen, describes its canopy cover as the perfect place to serve afternoon tea.

River Birch in MG Karen Strimple's Landscape
The ability of River Birch to tolerate soggy conditions is augmented by its ability to also tolerate higher summer temperatures than the rest of the birches, as well as its high resistance to the bronze birch borer, which is a major pest of other birches.

River Birch in MG Karen Strimple's Landscape
Because of its native status, ability to tolerate wet, and warm conditions, and pest resistance, River Birch is recommended for use in riparian buffers and other restoration sites alongside streams and reclamation sites after strip mining for erosion control. These characteristics also make it an excellent choice to anchor a rain garden. A six year old specimen can be viewed in the Master Gardener Woodland Meadow and Native Habitat demonstration garden on the Franklin Farm campus.

Learn more about Plants with Winter Interest:

Winter Interest in MG Iris Master's Landscape and Other Penn National Gardens
Nandina - Heavenly Bamboo
Landscaping for Four Seasons of Interest
Plants With Winter Interest - Part 1 - Partridge Berry
Plants With Winter Interest - Part 2 - Snowdrops
Plants With Winter Interest - Part 3 - Stinking Hellebore
Plants With Winter Interest - Part 4 - Native Jewel Orchid
Plants With Winter Interest - Part 5 - Lavender
Plants With Winter Interest - Part 6 - Witchhazel
Plants With Winter Interest - Part 7 - Paperbark Maple
Plants With Winter Interest - Part 8 - Eastern Teaberry or Wintergreen
Plants With Winter Interest - Part 9 - Harry Lauder Walking Stick
Plants With Winter Interest - Part 10 - Coral Embers Willow
Plants With Winter Interest - Part 11 - Corkscrew Willow
Ascot Rainbow Spurge - a Year Round Delight

2 comments:

  1. I use the bark- beautiful papery, for crafts and to enhance homemade papers. Another benefit to having this tree.

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  2. Ooh!. Great idea, Carol. Send me some pictures and I'll do an update using your work.

    ReplyDelete