Heavy snow can be tough on trees and shrubs. The native spruces, both black and white, as well as the balsam firs of northern Minnesota grow in spire-shaped forms, like a steep-pitched roof, allowing the snow to slide off. But snow still gets caught on the boughs. It's beautiful to us, yet research shows that a single 40-foot balsam could end up holding more than 6,000 pounds of snow.

Many would agree that it's the snow that contributes most to the Minnesota winter landscape, and a snow-covered evergreen is one of nature's most splendid sights. In the Twin Cities area we can expect to see snow-covered evergreens for about 30 to 40 days a year, as wind and thaws will remove snow the rest of the time.

There is nothing like a conifer to grace the winter scene, and by planting pines, firs and spruces we can make our city more livable. Not only are these trees attractive and resilient to our northern climate, but they fill in for deciduous trees that drop their leaves and look bare and cold in the winter. When maples, oaks and cottonwoods lose their leaves in the fall, evergreens provide our neighborhoods with some bulk. They protect from the cold winds, give us privacy and make us feel sheltered as they add their shades of green to the winter scene. Evergreens also provide food, not to mention nesting and roosting places, for birds and other animals.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.