Bark

Bark

Garden Clippings for Jan 17, 2026

When we think of bark on a tree, we tend to compare it to the skin of a human. Take a close look at both and you will find the similarities remarkable.

The primary function of both bark and skin is to protect the material within and beneath it. In our Grade 7 science class, we learned that xylem and phloem, the pipes that bring water and sugars up and down, sit within the inner layers of bark. Without bark’s layers of protection, the tree would be vulnerable to weather, insects and moisture loss.

Unlike skin, bark’s inner layer is made of living material, while the outer layer is quite dead. The tender inner bark is protected by the hard outer bark.

When a tree is young, its bark is smooth, like the skin of a baby. As the tree ages, its bark becomes tougher, eventually becoming more wrinkled.

If a tree becomes injured, its healthy cells immediately get to work, first callousing the wound, followed by creating new plant tissue that will eventually become inner and outer bark. For human skin, the process is similar, but likely quicker to heal.

Unlike human skin, bark takes on many forms, colours and textures. The Canadian Paper Birch is easily recognized by its smooth, white, thin bark. Paper Birch is noteworthy for its ease of peeling, flexibility, and water holding capacity, making it the wood of choice for birch bark canoes.

Another easy-to-recognize bark is Sycamore, noted for its smoothness and colour. Sycamore’s brown skin continuously sheds, revealing light green skin underneath.

A good number of trees have bark that is fissured, which can be described as rivers and valleys that weave vertically. The bark of Poplars eventually become heavily fissured with crevices that can run 5 cm deep, while White Oaks, Ash, and Maples have fissures that won’t be much more than 1 cm deep.

The bark of many Pines and Firs is scale-like, characterized by loonie-sized discs or plates that cover a tree. As these conifers mature, the bark plate layers remain thin enough for the tree to breathe and thick enough to provide protection.

Oaks, Chestnuts and other nut trees are able to produce tannins, which act as insecticides to deter harmful pests.

Beech trees have smooth grey bark that is easy to scratch your name on its surface, giving rise to its nickname, the Initial Tree. Another nickname for Beech is Elephant Stump, because their trunks bear a remarkable resemblance to legs of an elephant.