As temperatures drop and the days get shorter, Minnesotans think of putting the garden to bed for the season and perhaps putting their feet up for the winter. But there's one more task that homeowners can do now, with benefits that stretch far into the future.
Fall is the best time of the year to plant trees. The heat and dryness of summer are gone. And in fall, trees will focus on putting down roots rather than growing branches and leaves.
Evergreens should be planted very soon — they need to get their roots established before the ground freezes because they are sensitive to drying winter winds — but deciduous trees can be planted well into October.
Properly planted in a good location, trees may live for decades, so choose the tree and your site carefully. You don't want to plant a tree that could reach 60 feet in height under a power line. If you're a gardener, don't plant a walnut tree, which has chemicals in its roots that inhibit growth of other plants. Some trees grow best in a bit of shade, while others are better at coping with urban pollution or salt.
Forestry experts at the state Department of Natural Resources believe our changing climate will make it harder for trees like aspen, paper birch, tamarack and black spruce to thrive. Trees that should adapt well include lindens, black cherry, northern red oak, bur oak, sugar maple, red maple and eastern white pine.
Don't focus too much on buying a big tree. Smaller trees suffer less from being moved and may have faster early growth. The University of Minnesota Extension Service has a good guide to tree selection here: extension.umn.edu/tree-selection-and-care/recommended-trees-minnesota.
Once you have your tree, preparation is everything. Dig a hole that's a foot or two wider than the tree's container. Loosen the soil at the bottom of the hole. Now comes a critical step: figuring out what's going on with those roots before you plant.
Remove the tree from its pot, and gently scrape the surface soil away until you find the first pencil-thick lateral root coming off the trunk. Then take a sharp knife or pruning saw and "box" the roots — cutting the rounded sides of the root ball into a square. Cut a crisscross across the bottom to loosen the roots there.