Using Shrub Shelters
To avoid damage from winter weather to shrubs, you can build or buy a shelter within which to house the shrub for the winter. There is little to lose when sheltering a deciduous shrub (one that loses its foliage for the winter), as it provides minimal visual interest on the landscape. There are three main options for a shrub shelter:
Build a shrub shelter out of natural materials. Build an A-frame (also known as a “snow frame”) out of store-bought lumber. Buy a snow frame, which are available at some hardware stores.
Shrub shelters come in a variety of sizes and materials, though all materials must be able to withstand winter weather. For all shelters, you are essentially building a framework around the shrub that will support a roof to protect the shrub from snow, ice, and winds. For instance, a shrub shelter made out of natural materials can use a framework of wooden poles supporting a roof of evergreen boughs. Make sure never to use black plastic–it can cause extreme temperature fluctuations that may damage your plants.
Using Tree Wrap
Because the foliage of evergreen shrubs provides beauty to the winter landscape, you likely won’t want to cover it with a shrub shelter. But you still might need to offer some winter protection to your evergreen shrubs to prevent injuries from harsh conditions, and that’s where tree wrap is useful. You can purchase commercial tree wraps made of burlap netting at many hardware stores. Then, simply bind the shrub “mummy style” in the wrap. The shrub’s limbs will be pulled toward its trunk and supported, so they won’t snap under the strain of heavy snow, ice, or strong winds. This method is useful if you are expecting a severe winter storm. Once the conditions are calm again, you can unwrap your shrub to enjoy its beauty. A bigger challenge to evergreen shrubs than snow and ice is often drying winter winds, which can kill foliage. To combat this, you can make a windbreak out of tree wrap. Create a wire cage around your shrub with four wooden poles at each corner and chicken wire stretched between them. Then, stretch the burlap tree wrap across the wire and staple it to the poles.
Using Mulch
Snow cover insulates soil and helps prevent it from reaching killing temperatures. In fact, shrubs typically suffer less winter damage during a snowy season than winters without much snowfall. Mulch can help to insulate a plant’s roots over the winter, but incorrect application can end up doing more harm than good. Follow these tips if you plan to use mulch for winter protection:
When to apply: Apply mulch in fall, before first freeze, covering the entire root zone. Don’t pile mulch against he plant’s trunk.How much: Apply 2-3 inches for insulation from freezing. Use wood chips, straw, or even evergreen boughs to protect the root zone.When to remove: In the early spring, you can remove excess mulch, but leave a layer to prevent weeds and maintain soil moisture.
Fall Watering
Although we don’t necessarily equate wintry conditions with desert conditions, the winter landscape in cold climates is like a desert because plants can’t draw water from the frozen ground. Thus, proper watering in the fall can be an effective means of minimizing injury over the winter. Here’s the general guideline to follow:
Water plants well throughout fall. Water plants consistently and thoroughly, applying enough water to moisten the soil to a depth of 8-10 inches at least once a week until freezing temperatures arrive.
Watering plants well in autumn will allow them to transition more smoothly from the growing season into the dormant season. Even in cold weather, leaves and needles lose water through transpiration. The deep watering will help to sustain the plants over the winter. Make sure to do this before the ground freezes, so the water can reach the roots.
Fall Pruning
Watering shrubs properly in the fall is not the only “preventive medicine” to help them through the winter. Proper pruning also can go a long way toward winterizing them. Here’s how to know when—and when not—to prune:
Don’t prune in the early fall. Pruning at this time can encourage tender new growth that’s vulnerable to cold weather. If you need to prune evergreen shrubs, wait until late winter or early spring. But in the late fall you can remove weak branches that might otherwise snap over the winter. Early blooming deciduous shrubs are generally pruned after they have finished flowering in the spring. Later bloomers are generally pruned in early spring. In the late fall you can remove any weak, diseased, or dead branches on them.