Our winter weather conditions can present challenges for landscape shrubs — too cold, too warm, too wet, too dry, too much snow, not enough snow — and any combination of those should be expected. And, even though it is nearly impossible to prevent all damage, the savvy gardener needs to prepare for the worst, and that means employing a variety of practices to keep landscape shrubs as healthy as possible through the winter months.

According to the University of New Hampshire Extension, good shrub care begins in the fall with proper irrigation. This is especially important with evergreens. Healthy plants are better able to withstand whatever Old Man Winter throws at them. That means that the healthier your shrubs are before going into winter, the better they will be able to tolerate adverse conditions.

Windbreaks — Rhododendrons and other broadleaf evergreens, are particularly susceptible to drying out (desiccation) in the winter months. In cold weather, leaves and needles can lose water in a process called transpiration. This water loss is greatest during strong winds and mild sunny weather. During times when there are extremely cold temperatures, when the ground freezes, this can cut off the roots’ supply of moisture. Leaves begin to desiccate and turn brown as water is transpired faster than it can be taken up,

Erecting windbreaks made of burlap or canvas attached to frames around the plants can help reduce desiccation. Place barriers on the side of the prevailing winds. Some plants can be completely wrapped. Note: Never use black plastic as it causes extreme temperature fluctuations. Offering an extra degree of protection, burlap wrapped plants are less likely to be browsed by deer.

Anti-desiccants can be helpful, but only if applied correctly. Applied incorrectly, they can damage foliage or simply be ineffective. Read and follow product label instructions carefully. Generally, anti-desiccants are best applied when temperatures are around 40-50 degrees, giving good foliage coverage. Applied before plants are in dormancy can damage them by trapping excess moisture in foliage, which would eventually freeze and rupture leaf cells. Apply sprays to both upper and lower surfaces of foliage. Plants lose water through both the upper and lower surfaces of their leaves.

Mulching — Aside from the old adage that snow is “poor man’s fertilizer,” we learn that snowy winters are often best for tree and shrub survival. Few consider snow as Nature’s mulch, but snow actually insulates the soil and helps to prevent it from reaching a killing temperature. Snow also insulates against the destructive freezing and thawing. If only we could always count on a good insulating blanket of snow. During times where there is little snow to insulate roots, woody plants are more likely to suffer damage from extremely cold temperatures. To counter that, it is recommended to apply at least two inches of wood chips or straw over root zones, or use evergreen boughs. Be careful to avoid placing mulch against trunks which can result in damage or disease. In the spring, that mulch can be removed and added to the compost.

Plants and placement — In truth, proper plant selection and placement go a long way toward avoiding winter damage and plant survival. Putting the right plant in the right place is always the best course. Take note of how your landscape is situated, from which direction the worst of the winter weather hits, and observe sun exposure as well. Some shrubs, like evergreens, are especially susceptible to wind-burn.

Broadleaf evergreens such as rhododendrons, are susceptible to drying out from winter’s frigid winds. Pine needles make a good mulch to protect the roots of this acid-loving shrub. Photo by Lynette Walther.

Oh deer — An important consideration on plant choice is the possibility of deer damage. Winter months can turn normally shy wildlife to turn to lush landscapes, especially those with examples of arborvitae (Thuja occidentalis) and yew (Taxus sp.) available. Repellents are available and generally work when applied correctly and often, though those that elicit a fear response are most effective. Fencing and/or barriers are also suggested.

Shrubbery adds a lot to our landscapes, and those shrubs can represent a sizable investment. So keeping them healthy and thriving through the winters and beyond is what we hope to achieve. Spend some time and attention to them throughout the coming weeks and months, to help insure they do, and you’ll be rewarded with years of healthy greenery.

Lynette L. Walther is the GardenComm Gold medal winner for writing and a five-time recipient of the GardenComm Silver Medal of Achievement, the National Garden Bureau’s Exemplary Journalism Award. She is a member of GardenComm and the National Garden Bureau. Her gardens are in Camden.