Air conditioning creates a comfortable indoor living space by regulating air temperature and humidity. Because the unit interacts with outside temperatures in order to cool the home, warm outside air causes the unit to work harder, which increases the need for electricity. One way to save energy costs is to shade the air conditioning unit without restricting air flow. When planning a landscape, look for the best trees to shade an air conditioning unit.
The Eastern Redbud (Cercis canadensis) is a small tree appropriate for planting in United States Department of Agriculture hardiness zones 4b through 9a, which include most of North America. It is a small tree -- growing to 20 feet -- that provides year-round beauty with attractive pink or red blooms in the spring, followed by attractive foliage. In the winter, the smooth bark contributes to an interesting landscape. The lower limbs can be trimmed in winter to provide air circulation to the air conditioning unit, and the top limbs have a spreading habit that provides shade.
Saucer Magnolia (Magnolia x soulangeana) is a small, deciduous tree growing to 30 feet tall. It provides large, tulip-shaped blooms in the spring on bare branches, followed by dense foliage. This magnolia is suitable for growing in USDA zones 4 through 9.
The smoketree (Cotinus coggygria) is a small blooming tree suitable for growing in USDA zones 4 through 9. The foliage may be green or purple depending on the variety. Because it grows best in full sun, the smoke tree is a valuable shade tree for small, dry places, such as near a sunny, central air conditioning unit location. The interesting plumes appearing in mid-summer have the appearance of "smoke" from a distance.
The Kousa dogwood (Cornus kousa var. chinensis) grows best in USDA plant hardiness zones 5a through 8b. It provides similar spring blooms as the Flowering Dogwood (Cornus florida) but is disease resistant. Also, the bloom period is longer. The bark has an interesting texture, and it becomes an attractive tree when the lower limbs are removed to provide air circulation to the air conditioning unit while the tree canopy provides energy-saving shade.