This week: Winter Is for Birches
Hello!
Imagine a winter landscape. Maybe you pictured a stand of evergreens punctuated by the bright white bark of birch trees. While they are lovely year-round, birch trees stand out in the winter just as other deciduous trees fade into the background. Let’s focus on two native birches often used ornamentally: one for its white color and another for its peeling nature.
Gray Birch (Betula populifolia) is a white-colored birch native to the Northeast. In Pennsylvania, it is naturally found in the eastern and northernmost counties (the tree pictured here was intentionally planted at Keystone State Park in Westmoreland County). Unlike Paper Birch (B. papyrifera) and River Birch, Gray Birch does not have peeling bark. Instead, the mature bark is chalky white with triangular black patches at the branch connections (in the armpit, if we’re familiar).
River Birch (Betula nigra) is native to the Mid-Atlantic and Southeastern United States and is commonly found along streams, where it purifies water, enriches the aquatic habitat, and prevents erosion. You also can find it in practically any nursery or big box store selling trees. It’s highly ornamental with attractive brownish-peach peeling bark. On young trees, the bark peels away in papery sheets. As the tree matures, the peeling bark grows chunkier and more rough-textured.
Growth Habits
Both birches are fast-growing. Gray Birch grows 20 to 40 feet tall, while River Birch can grow up to 70 feet tall. Because they have narrow crowns, they are sometimes planted in tight spaces and small yards. In the fall, the leaves turn yellow.
The Trouble With Common Names
Confusingly, Gray Birches are sometimes called White Birches, which is another common name for Paper Birches. To make matters worse, one popular Gray Birch cultivar, ‘Whitespire,’ was mistakenly marketed as Japanese White Birch (B. platyphylla) until recently.
River Birch also has common name woes, as they are sometimes referred to as Red Birch (why!) or Black Birch, probably due to the nigra in its botanical name. Unfortunately, Black Birch is also the common name for B. lenta, the key ingredient in birch beer. These are all good reasons to use botanical nomenclature instead of common names!
Elsewhere:
Looking for a highly readable native plant reference book? Try The Northeast Native Plant Primer by Uri Lorimer of the Native Plant Trust. It covers 235 plants with brief, information-packed snippets and big pictures. I love big pictures!
Happy New Year!
Julie