Old Man Winter seems overly eager to make his annual debut. Throughout the past week, unseasonably frigid weather and biting winds typical of mid-winter have offered a sneak preview of the chilly days that lie ahead.
Old Man Winter seems overly eager to make his annual debut. Throughout the past week, unseasonably frigid weather and biting winds typical of mid-winter have offered a sneak preview of the chilly days that lie ahead. Each morning, the tightly furled leaves of rhododendrons have provided a preliminary gauge of the bitter cold temperatures, reinforced by the shimmering, silver-dusted covering that blanketed my lawn. A thin layer of ice has already formed over my water garden and even the sturdiest evergreen perennials lie limp in response to the plummeting thermometer. Gratefully, we have not had to endure the added insult of a premature snowfall.
For the next four to five months, most of our woody plants will remain dormant as fluctuating temperatures, chilly winds, snow and ice challenge their very existence. Most gardeners have a major investment in the trees and shrubs growing in their landscapes. Even if these plants were purchased as small specimens, as they mature over the years, their value increases exponentially. Should they succumb to adverse conditions during the winter months, the cost to replace these plants with similarly sized varieties can be prohibitive.
Evergreen plants, especially boxwoods and broad-leaf shrubs including rhododendrons, azaleas, mountain laurels, Leucothoe, and hollies, face the greatest hazards. Subjected to desiccating winds and winter sun, their leaves may be scorched, particularly during the latter half of the winter. Many of these shrubs have superficial root systems. Several inches of shredded bark mulch should be maintained over the root balls to assure moisture retention in the months to come. The mulch should not come into direct contact with woody stems, as this can potentially suffocate the plants, promote diseases, and encourage rodent and insect intruders.
Shrubs or boxwood hedges growing in open, exposed locations, or evergreens that have experienced winterburn in past seasons will benefit from the construction of a temporary windscreen to minimize damage. Install a series of stakes around these bushes and wrap with burlap, leaving the top open for air circulation. Anti-desiccant sprays, such as Wilt-Pruf, are available from your local nursery and can be applied to all evergreen foliages prone to winterburn. Make applications when temperatures are above freezing in late November or early December and again in early February to further protect their leaf surfaces.
The leaf and flower buds near the tips of dormant blue and pink hydrangea stems may be similarly damaged by winter desiccation. These showy summer-bloomers produce their flowers on “old wood;” this means that their existing woody stems and the tender green buds along these branches must survive the cold and the dry breezes that winter brings. To ensure blossoms next season, construction of a burlap windscreen may be helpful to protect plants growing in exposed areas. Fill the interior space with white pine needles or oak leaves. Last winter, during our balmy January thaw, the application of an anti-desiccant spray to the swelling leaf buds along the stems enabled my Nikko blue hydrangea to produce its best floral display since its initial planting 15 years ago. The new hydrangea introduction, Endless Summer, blooms on both old and new wood,ensuring blooms despite winter chills, but for a longer season of bloom, similar protection could be applied.
Few gardeners can resist the temptation to grow roses despite their demanding cultural requirements. The introduction of numerous lower maintenance cultivars has appealed to some, but many rose fanciers still succumb to the seductive beauty of the hybrid tea roses that tend to be the most challenging and require special attention in order to survive our harsh New England winters. Prior to applying winter protection to roses, remove all dead or diseased shoots and lightly trim especially tall canes. Be sure to rake up and dispose of rose foliage to minimize diseases overwintering in the ground surrounding your plants.
Protection of the bud unions of roses, especially the fist-shaped grafts of hybrid teas, is crucial for their survival during the coming months. This knob should have been planted 1 to 2 inches below the surface, but nursery pots are rarely deep enough to cover the graft and most of us are inclined to plant the rose bushes at the same level as they were grown in their container. To protect this critical growth point, a mound of fresh soil, bark mulch, or well-draining compost should be applied to the base of the plant. This cone-shaped mound should be 6 to 12 inches high and completely cover the crown. Use soil from a vegetable garden or other source rather than pulling soil together from around the base of your roses as you risk exposing their shallow roots making them more susceptible to the cold. Apply a layer of mulch to the mound once the ground freezes. Bagged soil and mulch are still available at many local garden centers.
In exposed, open areas, additional protection for the canes may be advisable. A cylinder of wire mesh can be placed around the protective mound to help hold the soil and mulch in place and subsequently filled with oak leaves or pine needles. Canes may also be wrapped with burlap. Special rose cones can also be purchased from catalogs to protect the bushes through the winter months.
Slightly milder temperatures are predicted for the holiday week, hopefully allowing suitable weather for passionate gardeners to protect their valued treasures. As I make these last minute preparations for winter weather, my thoughts turn from trimming my gardens to trimming my home for the holiday with fresh greens from my garden.
Suzanne Mahler is an avid gardener, photographer and lecturer who has been developing the 1.5-acre property surrounding her home in Hanover for more than 30 years. Her weekly gardening column Green Thumbs Up has appeared in Community Newspapers for more than a decade. She is a member of two local garden clubs, past President of the New England Daylily Society, an overseer for the Massachusetts Horticultural Society and is employed at two garden centers.