As the gardening season comes to a close in the Midwest, there are some important tasks we should consider to protect our gardens from the harsh conditions of winter. Protection efforts in our gardens in advance of the onset of cold and blustery weather goes a long way in helping to safeguard our investment of plants, time, and tender loving care and to minimize avoidable frustrations. As you’re running down your fall to-do list, keep the following winter protection strategies in mind.
Leave some of your garden cleanup for the spring
While tidying up the yard and garden in fall before the snow flies is a long tradition in the Midwest, you also need to decide what can be done now and what can be left for spring. Tasks like raking and collecting leaves, cutting back perennials, and doing a final lawn mowing are typically on our autumn to-do lists as the temperature dips. Research has shown that there is value in leaving a certain amount of debris (vegetative material) out in the garden over the winter. These dormant layers, including some fallen leaves and flower seed heads, can provide support for local wildlife in terms of shelter and food. There is certainly merit to selectively removing plant debris that might foster diseases, result in heavy reseeding, or present other challenges the following year. However, much of our garden debris, when left intact, will help support pollinator and wildlife diversity in our garden spaces as well as provide a natural layer of protective winter mulch for our plants.
Supply plants with regular water throughout fall before the ground freezes
The importance of continued watering until the ground freezes can’t be overstated. Consider the value of water for woody plants that, while dormant, still need available moisture to minimize the stresses of lengthy winter conditions. That available moisture, applied regularly before the ground freezes solid, will also benefit those plants in spring as they generate new growth. Moist soil also holds more heat than dry soil, which will help minimize root stress by avoiding the severest of temperature fluctuations. Be sure to identify and address prewinter watering needs in appropriate areas under eaves or other dry spots that can use some additional attention. Of course, before the freezing weather hits, be sure to winterize and protect your watering sources or irrigation systems too. Turning off water to hose spigots and pulling up and storing hoses and sprinklers helps to prevent freezing damage to water pipes and extends the life of your water delivery tools.
Install a barrier around plants at risk of wind and animal damage
Specific plants may benefit from the addition of a physical barrier prior to winter to minimize the effects of drying winds. For instance, well-secured burlap (or similar materials) can act to mitigate harsh winds and potential winter burn on choice evergreens or newly installed or marginally hardy woody plants. The little extra protection, which should allow some air circulation, can make all the difference over those fierce winter months.
At the same time, hungry critters (especially deer) can also be detrimental to plants in winter. There are many approaches to protect woody plants from deer browsing and the unwanted attention of other nibblers. While this is a vast topic with many recommendations, I’ve found that a tightly secured, half-inch gridded bird netting is quite effective in eliminating most browsing. The netting should also be pinned to the ground so it won’t be lifted or moved. I’ve seen many more elaborate ways of excluding deer, but this approach is also quite cost-effective.
Use a wire collar to hold winter mulch in place around plants
To keep an insulating layer of leaves or mulch in place around tender plants throughout the winter, add a circular collar of hardware cloth, chicken wire, or other rigid mesh around the plant’s base. This strategy is a great way to insulate the lower portion of the plant and root system. The collar should be 18 to 24 inches tall and secured firmly to the ground or even dug beneath grade a bit and secured. A common way to protect some roses (Rosa spp. and cvs., Zones 2–11) in the Midwest and other woody plants, such as more-temperature-sensitive hydrangeas (Hydrangea spp. and cvs., Zones 4–10), this insulating mulch should be removed in late winter or early spring to allow for new growth and better air and sunlight access to the lower portion of the plant. As a bonus, this collar also thwarts some winter nibbling by hungry critters.
—Mark Dwyer is the garden manager for the Edgerton Hospital Healing Garden in Edgerton, Wisconsin, and he operates Landscape Prescriptions by MD.