The first step in tree selection is to determine the type of tree appropriate for your property and your needs. Climate and soil play big roles. A date palm might have a tough time surviving a Minneapolis winter, for example. And a water-hungry willow would starve in the desert sands. Make sure that the tree species you are considering can flourish in your local climate and soil conditions (designated hardiness zone). And don't forget some of these other important factors:
Matching tree to site is a key part of the tree selection process. What is the size of the site on which your new tree or trees will be situated? How big will that spindly three-foot sapling be in 30 or 40 years? Will it be very large when fully grown, the best tree for a small front lawn in a city? On a large suburban lot, on the other hand, will a single small tree or bush be lost in a vast expanse of lawn?
A crucial factor to consider is proximity to buildings, sidewalks, driveways, streets, utility lines, overhead and buried, and septic systems. Trees spread our both above and below ground and branch overhang and root growth can cause considerable damage and incur considerable expense if a tree is poorly situated. Consider the planting location with respect to foundation, concrete and asphalt structures, and drainage structures.
Trees can play an important role in climate control. Deciduous trees planted on the south, west, and east perimeters of a lot will provide shade during the summer while allowing scarce sunlight through in the winter when leaves have fallen. Evergreens, on the other hand, planted on the north and west sides of a property, can reduce winter heating costs by serving as windbreaks.
Drainage is yet another issue to consider. Young trees do best when planted in good-quality, well-drained loamy soil. Heavy clays in poorly-drained sites present particular problems as many species of trees including white firs, yellowwoods, beeches, red oaks, and yews will not tolerate "wet feet". In all cases, stagnant water pooling around roots can lead to "root rot" caused by lack of available oxygen.
You can do a general test for soil drainage by digging a hole in the planting area and filling it with water. If the water hasn't drained away in a couple of hours, drainage may be an issue. In areas where drainage is a particular problem, planting in raised beds of 12 to 18 inches of well-drained quality topsoil may be a solution.
Soil quality in new subdivisions often presents tree-planting problems. Construction materials, in addition to creating unsightly and difficult-to-work rubble, can alter the soils fertility by raisigin or lowering pH. Chemical and petroleum spills, which often occur during building construction, pose additional concerns. In cases where soil contamination is severe, the only solution may be to scrape away the contaminated soil and replace it with good quality topsoil at a depth associated with your planting objectives.
Personal taste is another key consideration. Think of how different kinds of new trees can enhance the attractiveness of your property. Make a list of the kinds of trees you admire and think about how they would look. Consider how your selection will fill in the planting area over time. Make a few sketches or, if you don't trust your own artistic talent, consult available landscape design software, or a landscape designer. Dig the planting hole for trees and shrubs at least a foot wider than the diameter of the rootball. Dig it only as deep as the height of teh rootball, or even a few inches shallower to keep the plant from sinking deeper into the hole than intended. The planting depth should be the same as in the field where the plant was grown. Use the burlap to lift the plant into the hole. Once it is in place cut the twine and burlap from around the trunk. The remaining burlap and wire basket should be left in place. When filling the hole, be careful not to disturb the rootball. Firm the soil and settle it with water.