Why do birch trees shed

They are also more borer-resistant than most birches. Another birch tree grown as much for its peeling bark as for its fall foliage is the paper birch Betula papyrifera. Its fall foliage color is yellow. The bark of this tree is famous for another reason, too: as the material for birch-bark canoes. Grow this tree if you live in Canada or the northern tier of U. It's a native to this region, and it prefers cool temperatures. The fall foliage gray birch trees Betula populifolia is similar to that of the paper birch tree.

But gray birch trees grow in clumps, producing multiple trunks, and their bark, which does not peel, is not especially attractive. Despite the unappealing bark, the foliage this tree produces is quite lovely.

The height and spread are similar to that of river birch trees. Plant them in full sun to partial shade. Best grown in the northern part of the United States or in Canada. It can be grown in planting zones 3 to 9. In addition to its white bark and yellow fall foliage, the form of this tree provides landscaping interest. Plant it in full sun to partial shade. Its parent, Betula pendula , is the European white birch.

Another of the attractive non-white birch trees is the yellow birch Betula alleghaniensis. A tall tree 60 to 80 feet with a spread of about 30 feet, it has yellow fall foliage. But it derives its common name not from the color of its foliage, but rather from the color of its peeling bark.

This bark sheds like that of the paper and river birch trees. Speaking more accurately, the bark is silvery-bronze in color with hints of gold. Yellow birches should be grown in full sun to partial shade, in planting zones 4 to 7. Living organisms will naturally shed these. Healthy organisms will only shed the outer layer when a new inner layer is already in place. This new layer will often look different to the old outer layer. In birch trees, the new layer is often orange-colored, so many people think they are seeing the underlying wood, which is why they worry about the health of their trees.

What they are actually seeing is the new bark, and that new layer is still protecting the tree. Bark may also split before or after shedding. Again, this is normally nothing to worry about. Trees grow from the inside out. That means new internal tissue expands, and that can cause the outer bark to split.

It can be difficult to detect problems. However, insects really like to burrow in those grooves, so oaks produce tannins to make the tree taste bad. This bark sloughs off as the tree expands, a little like how snakes shed their skins.

Smooth barks have their advantages. Insects have a hard time burrowing into smooth bark. Also, as bark peels off, it gets rid of moss and lichen that thrive in the same damp environments as birch trees. Outer bark has an important job: protecting the tree. Removing it may harm the inner bark and cambium. The wood beneath that peeled section may turn black, and the tree will get sick or even die.

Katie Venit is a professional freelance writer who enjoys writing about everything, but especially food and drink, culture, the Great Outdoors, and education. Preferably all in the same story. If you'd like to work with her, email her at katie.