Kathy Zuzek, University of Minnesota Extension Educator
It’s official. Winter is more than half over. Are you feeling a bit desperate for warm temperatures and the color green? I spend every February dreaming of a trip to anywhere warm and green or of a kinder, gentler Minnesota where spring actually arrives in February. A quick look out of my window though always reminds me of how truly bleak our long winters would be without woody plants.
Imagine our winters without trees. The word “tundra” comes to mind with endless unbroken landscapes and unchecked winter winds. In fact, the word tundra comes from the Finnish word “tunturri”, meaning treeless plain. Now add trees back into the picture and winter, even in February, is not so bad.
Leaves have fallen from deciduous trees and our focus turns to the sheer size and bold architecture of many tree species. White oak (Quercus alba), swamp white oak (Q. bicolor), bur oak (Q. macropcarpa), red oak (Q. rubra), northern pin oak (Q. ellipsoidalis), and black oak (Q. velutina) are native and abundant in Minnesota, and their large size and gnarled branches add interest to a winter landscape (Figure 1). Weeping willows (Salix sp) with their height and dramatic yellow weeping stems are startling against a blue winter sky (Figure 2). Who can help but notice a female Kentucky coffee tree (Gymnocladus dioicus) this time of year with its coarse branches, textured bark, and large seedpods (Figure 3).
Evergreen trees add mass and color to our winter landscapes. The view of large, mature white pines (Pinus strobus) and red pines (Pinus resinosa) against snow and bright blue winter skies in eastern or northern Minnesota is an amazing sight (Figure 4). In a planted landscape, spruce (Picea) and fir (Abies) lend a formal air with their conical “Christmas tree” forms (Figure 5). Scots pine (Pinus sylvestris) with its wide crown and horizontal orange branches provides a less formal source of green in winter landscapes (Figure 6). Austrian pine (Pinus nigra) with its stout trunks, branches, and dark green needles adds a strong sense of mass to our winter landscapes (Figure 7).
Step in for a closer view of our winter landscapes and you will see texture and color everywhere. With leaves absent, the large flower buds on silver maple (A. saccharinum), red maple (A. rubrum), and Freeman maples (Acer x freemanii) give branches a beaded look. Nothing shouts texture like the cinnamon and ivory curling bark of a river birch (Betula nigra) (Figure 8), the flaky bark of three-flower maple (Acer triflorum) (Figure 9), the brown rustling leaves that are retained during winter on younger oak trees (Figure 10) or dried flower heads of hydrangea (Figure 11). The shiny red-brown bark of Manchurian cherry (Prunus maackii) (Figure 12) is beautiful on sunny or cloudy days. Dwarf conifers come in an amazing variety of form and texture in shades of green, blue-green, and gold (Figure 13). ‘Green Mountain’ boxwood (Buxus sp.), one of the few broadleaved evergreen plants hardy in Zone 4, is still a mass of green leaves in February (Figure 14). Many of our small trees and large shrubs are multi-stemmed plants whose twisting trunks and/or retentive fruit are full of texture and color: blue beech (Carpinus caroliniana) with its gray fluted stems (Figure 15), sumacs (Rhus sp.) with their red fruit (Figure 16), Amur maples (Acer ginnala) full of brown samaras (Figure 17), redbuds (Cercis canadensis) with seedpods, and tree lilacs (Syringa reticulata) with their masses of open brown seed capsules (Figure 18). We know crabapples (Malus sp.) for their beautiful and fragrant spring bloom, but many crabapple cultivars (‘Adams’, ‘Bob White’, ‘Centurion’, ‘David’, ‘Donald Wyman’, ‘Harvest Gold’, ‘Indian Magic’, ‘Ormiston Roy’, ‘Professor Sprenger’, ‘Red Jade’, ‘Red Jewel’, ‘Red Splendor’, ‘Sentinel’, ‘Silver Drift’, ‘Silver Moon’, ‘Sugar Tyme’,) retain their red, orange, and gold fruit through winter, adding color to gray winter days (Figure 19). European cranberrybush (Viburnum opulus) and our native American cranberrybush (V. trilobum), winterberry (Ilex verticillata), and barberries (Berberis sp.) also retain fruit through the winter. Masses of these vivid orange and red fruit are beautiful against a snowy backdrop (Figure 20). Red or chartreuse stems of our dogwoods (Cornus sp.) are another source of bright color during winter (Figures 21 & 22).
Step up to trees and shrubs during your winter strolls for a bird’s eye view and more winter interest awaits you. Have you ever looked closely at the branches of our ornamental cherries, plums, and almonds? The branches and trunks of these plants, all of which are members of the genus Prunus, are often covered with conspicuous lenticels (Figure 22), openings that allow gas exchange between the inner parts of plants and the atmosphere. The green stem of a burning bush (Euonymus alatus) edged with brown corky ridges is full of interest (Figure 24)as is the colorful fruit of a bittersweet vine (Celastrus scandens) wrapping around a pillar (Figure 25). The blue or violet berry-like cones of junipers (Juniperus sp.) (Figure 26) and the cones of pines (Pinus sp.), spruce (Picea sp.), fir (Abies sp.), arborvitae (Thuja occidentalis), andDouglasfir (Pseudotsuga menziesii) against a backdrop of green needles or scales are full of color and contrast (Figure 27). How about the beautiful texture, color, and softness of a fur-covered Magnolia (Magnolia sp.) bud (Figure 28)? It’s almost as if each bud has its own winter parka. Look at the buds of lilacs (Syringa sp.). They are plump and green, appearing as if they will open tomorrow (Figure 29). The male flowers or catkins of birch (Betula sp.) trees and their relatives are visible all winter, providing a light texture in plant canopies (Figure 30).
Look out across a vista, look up into a tree, or closely into a shrub and you will see that even in winter, our landscapes are packed full of interest. As you plan future landscapes, don’t forget to combine some of these plants into a collection of companion plants. Winter is a long season in Minnesota and a wise gardener plans for garden interest in winter as well as during our warmer months. The contrast of red dogwood stems, green pine needles, and oak leaves is a planting combination full of color and texture in winter (Figure 30) as is a grouping of ornamental grasses, and evergreens (Figure 32).