Winter has made itself known in the last couple of weeks in a big way. First snow and now bitter cold. Having furnace problems and kids that are crawling the walls because it's too cold to play outside has given me a new appreciation for milder temperatures!
It’s a stroke of luck for our gardens that we had a good layer of snow before the extreme cold hit. Even though snow itself is cold, it is an excellent insulator and prevents bitter cold temperatures from penetrating deep into the soil. The colder the soil gets, the higher the risk of damage to root systems of plants.
Snow insulation also protects plants, especially those sometimes called “semi-hardy” or labeled as “tender perennials.” Plants under a layer of snow are warmer than those out in the open. They also retain more moisture. Plants exposed to cold winter winds dry out much quicker than those protected under snow. While you can’t expect “tender perennials” to survive Central Illinois winters on a regular basis, a good layer of snow may help.
Snow also minimizes the freeze-thaw cycles that happen throughout the winter months. Winter sun on bare soil will thaw it out a bit, only to freeze again once the sun goes down. This causes soil heaving, which can break and expose delicate roots and plant parts to the drying wind. The perennial Heuchera, also called Coral Bells, is a common victim of soil heaving. Repeated freeze-thaw cycles are more damaging to plants than being at freezing temperatures for prolonged periods.
How can you protect your plants from heaving if there is no snow? Mulching plants after the ground has frozen can help protect them over the winter. We usually think the mulch is helping to keep the plants toasty warm for the winter, but the opposite is true. Adding mulch in the winter allows the plants and soil to stay cold, which minimizes damage from repeated freeze-thaw cycles.
Snow cover isn’t always a great thing for the garden. One critter that thrives with snow cover is the vole. Voles, which are very similar to field mice, typically don’t venture out into the open, preferring to stay hidden in tall grass and other vegetation to save them from predators like hawks.
With a blanket of snow in place, they can have the time of their lives beneath the snow undetected by predators. As the snow melts, keep an eye out for small trails or tunnels in the surface of your lawn and gardens. Unfortunately, voles feast on overwintering perennials and bulbs so that you may find increased levels of damage this spring.
Rabbits also tend to wreak more havoc than usual when snow is deep. Their snowshoe-like feet allow them to travel on the top of the snow, and they can reach new heights. So this spring when you find rabbit damage higher than what you think a rabbit can reach on your shrub or tree, it’s not because you have been invaded by giant rabbits — your local rabbits just took advantage of the snow drifts to find a meal.
As snow accumulates over the winter, the weight of the snow can cause damage to trees and shrubs. Gently shake or use a broom to brush heavy snow from shrubs or tree limbs if it appears to be weighing down the plant. But don't get carried away. Limbs that are bent over and covered in ice should be allowed to thaw naturally and later propped or staked to add support. Trying to move an ice-encased branch will likely crack and damage it.
Ice storms put an incredible amount of stress on trees. Depending on the size of the tree, a coating of ice can increase the branch weight by thirty times or more. Much of this added weight is highly dependent on available surface area.
Even if you don’t consider yourself a "gardener," proper pruning of trees is one way to protect your home or other structures on your property. Some of this can be a do-it-yourself adventure, but potentially unstable, very large limbs hanging over buildings or involved with power lines should be handled by professionals.
Despite the potential problems, and new landscape maintenance “to-do’s” generated by snow and ice, there is something to be said for the beauty of the world covered in white that makes most of us slow down a bit, at least for a day. Even if you hate everything to do with snow and ice, the harsh winter winds will give way to spring, sooner or later. Perhaps we will appreciate it just a little more this year.