Larry Hurley’s Photo Of The Week: Protect your young trees and shrubs this winter.

Protect your young trees and shrubs this winter. It’s a bit early in the season, but I’m a bit late providing a photo for Stephanie this week.

So, in the spirit of planning ahead, I offer up a photo taken in March of 2009, when Behnke’s had a plant-growing nursery in Lothian. We overwintered potted trees in long beds, with mulch covering the pots to provide insulation for the root systems from below freezing temperatures and to moderate winter temperature fluctuations. Because normally they are in the ground, root systems are often less cold tolerant than the above-ground parts.

What you are seeing in the photo is winter-feeding damage caused by rabbits, which ate the tender bark of these elms, girdling the tree. Without the xylem which is directly under the bark, the tree can no longer transport water from the roots to the top, and the tree dies. Voles (which look like mice with short tails) will also girdle trees and shrubs.

To reduce the risk of damage to young trees, move the mulch further away from the trunk going into winter–voles like to tunnel under mulch–and place a tree-trunk protector around the trunk for the winter. An added bonus of a trunk protector for young, thin-barked trees like maples trees is that they prevent another winter injury called frost crack. If it’s very cold and very sunny, the south-facing side of the tree heats up, and when the sun goes down it chills down very quickly and may crack. Trunk protectors prevent the trunk from heating up as much and slow the rate of temperature changes.

You might also make a fence/cage around shrubs or tree trunks with hardware cloth. This reduces the risk of vole, rabbit and deer browse. The winter photo of caged shrubs in the snow is in my back yard. In our Wisconsin winters, there is less for browsing animals to eat, so we may be more at risk here than you are in Maryland. I do recall that voles feeding on the base of boxwood shrubs is a big problem.

Your local garden center should be able to help you purchase the right material for your needs.