There is a false perception in the gardening world that fall is the end of the growing season. In fact, it is quite the contrary. Fall is an ideal season for planting trees, shrubs and other assorted plants. The key is encouraging good root growth. Planting trees and shrubs in fall enables the root systems to grow before the hot summer returns.
Smaller plants will be established before winter sets in, and get a head start over shrubs in the spring. Larger plants will also get a head start since a general rule of thumb is one year per one inch of trunk diameter.
Fall officially begins with autumnal equinox in late September. The ideal time to begin planting trees and shrubs is six weeks before the first sign of hard frost. September through November is the ideal time for tree planting because it allows the roots to become established before the ground freezes and winter sets in. However, it is highly recommended that you do not continue planting trees too late into the fall because this can have a negative impact on plant health.
Cooler, wetter weather is the perfect time for tree planting. With an increase in rainfall and cooler temperatures in the fall, less watering is needed. As tree shoot growth halts, the trees require less water because the days are cooler and shorter and the rate of photosynthesis decreases. Stable air temperatures also promote rapid root development. Soils stay warm well after the air temperature cools, also encouraging root growth. During shoot dormancy, trees grow to establish roots in new locations before warm weather stimulates top growth.
There are several benefits to fall planting. Trees planted in the fall are better equipped to deal with heat and drought in the following season. Another great reason to plant your shrubs in the fall is because you can pick your trees and shrubs by the fall color they produce. Avoid planting broad leaved evergreens in the fall such as rhododendrons, azaleas, boxwoods and hollies. If planted, provide them with protection from winter winds and have them treated with an anti desiccant. Some tree species that are recommended for fall planting include the maple, buckeye, horse chestnut, alder, catalpa, hackberry, hawthorn, ash, honey locust, crabapple, amur corktree, spruce, pine, sycamore, linden and elm.
Article from saveatree.com