by Matthew Olson

Winter is a quiet time of year in the garden.  The flowers are no longer blooming, the pollinators have begun hibernating and the plants are dormant.  A blanket of snow covers the landscape and allows us to take a break from outdoor garden activities.  We often miss the lush green growth of summer and eagerly wait for spring when the garden will burst into bloom once again.

The garden looks very different this time of year, but with some planning and creativity it can be just as beautiful as it was in summer.  Winter Interest refers to plants that look good during the winter months, and some of these plants look their best during the winter.  We’ll be looking at several trees, shrubs and perennials that will enhance your winter landscape and make the long winter months a little more enjoyable.

As a young boy growing up in Wisconsin, my favorite tree in our yard was a River Birch (Betula nigra).  The River Birch is well known for its beautiful exfoliating bark that is especially stunning during winter.  The peeling bark has different shades of colors that stand out nicely in the snowy landscape.  River Birch is often planted with clumps of 2-5 stems, which maximize the impact of the peeling bark.  River birch are beautiful trees at any time of year and grow well in areas that have moist soil and plenty of sun.  

A group of trees that really stand out during the winter are evergreens.  An evergreen is any plant that retains its leaves throughout the year, such as Pine, Spruce and Fir.  Evergreens come in many shapes and sizes.  They also provide shelter for birds and other wildlife in winter.  Mugo pines and Yews are a great choice for smaller landscapes, with many dwarf varieties that stay under 5 ft.  Balsam fir (Abies balsamea) is a native Fir that is common in Northern and central Minnesota.  It’s more shade tolerant than most evergreen trees and has glossy needles that stand out in the snow.  White Pine (Pinus strobus) is a great choice for larger landscapes, with soft feathery foliage that gracefully moves in the wind.

There are many unusual evergreens that can be planted in the landscape as well.  The weeping white spruce (Picea glauca ‘Pendula’) is a unique variety of the white spruce (Picea glauca) that grows very tall and narrow, creating a stunning specimen.  

In recent years, breeders have created many dwarf varieties of Pine, Spruce and Fir that will stay compact and can be used in smaller landscapes, giving us more opportunities for winter interest than ever before.

The majority of evergreen trees and shrubs in Minnesota have needles for leaves, but there’s a few evergreen shrubs that feature broad leaves.  The most commonly grown broadleaf evergreen is the Boxwood (Buxus) and Rhododendron (Rhododendron).  Boxwood are known for their green glossy foliage, and compact growth. These can be a great addition to your landscape.  Rhododendron are grown for their large pink flowers in spring, and they retain their leaves in winter.   You may notice the leaves of rhododendron curling during the winter, but don’t be alarmed because this is normal.  This is a process known as thermonasty, which is how the plants conserve moisture in the leaves during winter.   Site selection is very important to maintain healthy boxwoods and Rhododendron in Minnesota.  They should be planted in locations that are sheltered from the strong winds and winter sun to avoid winter burn.  Winter burn is caused by the leaves drying out due to wind and sun exposure, which results in brown leaves in spring.  Rhododendrons require an acidic soil with a PH of under 6.  A soil test is the best way to determine if you can grow rhododendrons in your landscape.  Evergreens are an excellent way to green up the garden in winter.

Another way to add interest to your winter landscape are crabapples.  Crabapples (Malus species) are primarily known for their beautiful spring flowers, but some varieties retain their showy fruit through the winter months.  The varieties ‘Donald Wyman’ and ‘Firebird’ have beautiful red fruit that stay on the tree during winter.  Most varieties of crabapple don’t retain their fruit all winter long but they do provide nutritious food for birds in early winter.  

Shrubs are a great way to make your garden look beautiful during the coldest time of year.  My favorite shrub for winter interest is the American high bush cranberry (Viburnum trilobum).  The highbush cranberry is a large shrub that has clusters of red berries that persist during winter.  

A well known shrub for winter interest in Minnesota is the red twig dogwood (Cornus sericea).  The red stems of dogwood really stand out in the snow, and if you’re looking for more than just red stems, you also could plant dogwoods with yellow stems!  The varieties ‘Flaviramea’ and ‘Buds yellow’ have gorgeous yellow stems that contrast nicely on their own or mixed with red stem varieties, such as ‘Arctic Fire’. 

The seedheads of  Panicle Hydrangeas (Hydrangea paniculata) also enhance the winter landscape, and can make a great addition to a winter container. 

The final group of plants we’ll look at are the perennials.  Most perennials look good in summer then dieback for the winter, leaving little winter interest for us to enjoy.  But there’s a few perennials that shine during the darkest time of year.  Ornamental grasses stand tall and provide beautiful texture and color during the winter.  Some especially nice grasses include switch grass (Panicum virgatum) and silver feather miscanthus (Miscanthus sinensis ‘siberfeder’).  Karl Foerester reed grass (Calamagrostis x acutiflora ‘Karl Foerester’) is another reliable performer for the winter landscape.  

In addition to grasses, black eyed susan (Rudbeckia fulgida), Purple Coneflower (Echinacea purpurea) and sedum (Sedum) feature tall seed heads that stand up in the snow and provide an easy source of food for birds to enjoy.

Winter interest is a great way to keep the garden looking beautiful year round, and now is a perfect time to enjoy the winter interest in your garden and dream of ways to make your landscape even better in the future.