Trees enhance virtually any landscape, especially when they are carefully selected and placed. In the high mountain state of Colorado, where plant hardiness zones range from 2b to 7a, choosing trees suited to the local climate is very important. Visit nurseries and garden centers in your area to get ideas and information. Local volunteers with the Colorado Master Gardener Program also have a wealth of gardening and tree knowledge that is yours for the asking.
Select a well-drained site to plant your tree. Consider the size of the tree when full grown and whether it will be too close to buildings or power lines. The ideal soil for most trees is sandy and slightly acidic. Most of the soil in Colorado is high in clay. You will probably need to add sand and organic material before planting your tree.
Measure the width and height of the root ball. The part of the trunk that widens just above the roots is known as the flare. After planting, the flare should be about 2 inches above ground level. Dig a hole to the correct depth and make it twice the width of the root ball. Loosen the soil around the sides of the hole so that the roots can easily penetrate. If the Colorado soil is high in clay, add sand and plenty of peat moss, yard clippings or leaves. Mix well with the soil in the hole.
Cut away any twine wrapped around the tree before planting. Place the root ball in the center of the hole. Double check the depth by laying the shovel across the hole and measuring to the flare. Cut the twine from the root ball and push the burlap or other wrapping down the sides. Larger trees may have a metal basket around the root. Push the top ends of the basket down so they will be well below the surface after backfilling.
Backfill the soil 4 to 6 inches at a time and firmly tamp it down with your foot each time to hold the tree in place. Make a ring of soil roughly 6 inches high around the edge of the hole. This help to keeps water close to the tree.
Place two planting stakes (three for large trees) about 12 to 18 inches from the trunk on opposite sides of the tree. Pound the stakes in until they are very secure. Cut strapping pieces about 36 inches long. Loop the strapping around the trunk, cross it, and tie or nail it to the stake. Make sure the straps are taut but not too tight. When done correctly the strapping should be in the shape of a figure eight. Cut off excess strapping.
Water the tree and spread 3 to 4 inches of mulch around the tree out as far as the soil ring. A good mulch can be made of wood chips, bark, straw or leaves.