Disease-Resistant White Paper Birch Trees in Wisconsin

Description

• In Wisconsin and throughout its northern hardiness zone, paper birch grows between 50 and 70 feet tall, with a spread of at least half its height. The trunk and branches feature the characteristic exfoliating bark. The flowers are in the form of catkins. Male catkins are brown, while female catkins are yellowish green. Paper birch leaves are oval-shaped and dark green in summer, before turning vivid yellow in fall. The tree is a medium to fast grower, gaining 18 to 24 inches per year.

Birch Pests

• Paper birch trees growing in Wisconsin are generally less stressed by climate than those grown in the warmer parts of its hardiness range (USDA zones 6 or 7). This is one of the factors that make it more resistant to the bronze birch borer, which has decimated populations of the similar European white birch (Betula pendula), also hardy in USDA zones 2 through 7. Less environmental stress also makes paper birch more resistant to canker, a fungal disease caused by Cytospora fungi. Canker girdles affected trees, killing the portions of the tree above the canker.

Varieties

• "Renaissance Reflection" (Betula papyrifera "Renaissance Reflection") was bred in Wisconsin specifically for birch borer resistance. It grows rapidly and is also more heat tolerant than some other varieties. "Prairie Dream" (Betula papyrifera "Prairie Dream"), developed in North Dakota, is another borer-resistant variety, with a growth habit that becomes a broad oval as the tree matures. Its hardiness range extends down to USDA zones 2b to 3. "Snowy" (Betula papyrifera "Snowy"), bred in Michigan, is also a fast-growing, borer-resistant variety with dark green foliage.

Uses

• In Wisconsin and elsewhere, paper birch is an excellent specimen tree, especially because its white bark peels back to reveal orange-brown bark underneath. The trees are large enough to be useful in parks and other large scale plantings as well. Paper birch is also suitable for native plant gardens, provided there is enough space. "Chickadee" (Betula papyrifera "Chickadee"), a columnar variety, might be a good choice where space is more limited. In naturalized areas the trees add fall color.