If winter seems like a blah season colored in shades of gray, blue and brown, maybe you just aren’t looking closely enough.

Spring’s brilliant blossoms may be long gone, but tree bark is at its best now when the leaves have plummeted to the earth, the berries have been nibbled away by the birds and all that’s left is a textural kaleidoscope.

Bark is much more than a rough blanket of protection. Each tree species has a unique pattern that serves as a means of identification, and in that armor we can see the hardships and bounties of that particular tree, guess at its age and envision the weather calamities it has endured.

The resistant coating might be red, green-gray, white, orange, striped, thorny, smooth, rough, furrowed or papery. The layers might peel away to reveal a mosaic of colors. The deep shadows of the sunrise might look like abstract art on a thick, old trunk. Regardless, the beauty is there, we only need to take note.

The science of bark

“To the trained eye, most tree species can be identified by the bark and buds,” says Charles Barden, associate professor of forestry at Kansas State University. “This is useful since the leaves are off the trees from November to April.”

Bark textures are divided into at least 18 types, from smooth (like the beech tree) to spiny (like the locust). The variations in markings, colors and texture denote not only the type of tree, but even its age.

The bark is a portal for the distribution of food in a tree.

“Bark is made up of two kinds of tissues. (One is) the inner bark, also called the phloem layer, which is just one cell thick and is used by the tree to carry sugar made in the leaves down the trunk and to the root system,” Barden says. “The outer bark is what we see and is made up of dead cells, which serve to insulate and protect the delicate tissues beneath (phloem and cambium).

“Old trees can have very thick bark, which can make them quite resistant to fire damage. For instance, some large cottonwoods in this area may have an outer layer up to 3 inches thick.”

So the inner layer of bark, or the phloem of the tree, is moist and soft, allowing for the passage of food. This layer also rids the tree of waste by absorbing and locking it into dead cells and resins. Older trees have thick bark because annually a layer of the inner bark hardens and becomes part of the outer bark. As an example, the bark of the giant and ancient West Coast Douglas fir tree may be more than a foot thick.

So what about the color variation in a tree’s bark? Why are some awash in brilliant colors while others are not?

“It has to do with the makeup of the layers of cells in the bark,” Barden says. “On sycamores, the outer gray bark flakes off and reveals light green and light gray bark layers. Other trees have homogenous bark layers, and they do not fall off in large pieces so the appearance does not change, much like an oak tree.”

Displaying bark

When thinking about the textural winter show that trees can provide, keep in mind that you’ll want to view your trees from inside to avoid the chill. So plant new trees with an optimal vantage point from an indoor perch.

Be mindful when using weed-eaters and mowers; gashes in bark can be entry point for pests. You might consider creating a bed around the base of the tree or a ring of mulch to avoid this problem. With some trees, like the birch, group plantings create a nice repeating pattern, adding impact to their bark display.

Barden says two trees with beautiful bark that are easy to grow in Kansas are the London Planetree and the river birch.

“The Planetree is a hybrid of the Native American sycamore, and it is not prone to a foliage disease that strikes the sycamore in wet springs,” he says. “It does get rather large (50 to 60 feet tall with a wide crown) – too large for some home settings. River birch does not get as big (40 to 45 feet tall with a narrower spread) and has attractive salmon-colored patches that are revealed as the brown outer bark peels away.”

So get out there, bundle up and take a slow walk around Lawrence. Look deeply at the trunks of trees, and you will find that the display is fantastic and awe-inspiring.

Some trees with interesting bark

¢ Red cedar

¢ Dogwood

¢ Bald cypress

¢ Sycamore

¢ Black cherry

¢ Japanese maple

¢ Carolina silverbell

¢ Shagbark hickory

¢ Paperbark maple

¢ Stewartia

¢ Beech

¢ Birch

¢ Snake bark maple

¢ Crape myrtle