Planting For Winter Interest

Can anything be done to alleviate the monotonous starkness of a northern Minnesota winter garden? If so, how can we achieve year-round color, interest and enjoyment as part and parcel of our general garden design? Fortunately, there are some hardy plants to choose whose function is to do just that.

In the shrub and tree category, there are few to challenge Salix alba Flame (Flame Willow) as the king of winter color. It grows to 20' under favorable conditions, with a width of 15'. Dark green leaves in the summer turn to a stunning golden yellow in the fall. The winter stems are a bright fiery orange-red that light up any wintry scene especially when the sun is low on the horizon. Reaching its fullest potential in full sun, it will also take some partial shade. A fast, compact grower, it is best used as a hedge or windbreak, or as a specimen plant rather than in a mixed planting. It prefers a good supply of water during the summer, but definitely should not be grown near a septic system.

A smaller, more compact shrub with lovely winter color is Cornus stolonifera Arctic Fire, a.k.a. Red-Twig Dogwood. Growing to four feet high, this dogwood has spectacular deep red stems in late fall through winter and into spring. More versatile than the Flame Willow, this non-suckering plant can be used in herbaceous borders without overwhelming its neighbors. Colors are best when planted in the sun. Like the Flame Willow, this shrub needs medium moisture, which means it will benefit from watering during long, hot and dry spells.

Of the perennial grass family, two hardy species will prove a valuable addition to the winter garden. Calamagrostis xacutiflora 'Karl Foerster' and Schizachyrium scoparium 'Little Bluestem'. Both have vertical growth habits with foliage reaching 2-3' and the flower stems reaching 4-5' (smaller for 'Little Bluestem').

'Karl Foerster' requires full sun, well-drained and fertile soils, while 'Little Bluestem' requires full sun and well drained, but less fertile, soils. Both are low maintenance plants. For winter interest, do not cut back the grass. The clumps of dried leaves turn tan or golden-tan, with the spent flower heads remaining upright during the winter for showy clumps of color. Seed-head sprays can be used in dry flower arrangements. As with most grasses, they are best displayed in clumps or massed in large scale groups.

Of the perennials, consider the family of upright sedums such as Autumn Joy and Matrona. Their two-foot high flower stalks, topped by an attractive mass of bronze-brown seed heads, will remain standing during winter poking through the blanket of snow that typically buries other perennials. To give maximum effect, they are best planted in massed clumps. Sedums prefer a drier,less fertile soil.