Planting Trees for Energy Conservation

Homeowners go to great lengths to conserve energy in this era of tight budgets and environmental awareness. However, many do not realize that the simple act of planting a tree can result in energy savings. The right tree planted in the right place provides wind protection, shade, and cool air, while adding beauty, privacy, and wildlife habitat to the landscape.

The right tree in the right place also means tree selection and placement to minimize conflicts with power lines and other obstructions. Many residential power outages are caused by trees interfering with power lines.

Trees can reduce summer temperatures significantly. Shading the roof of a house from the afternoon sun by large trees can reduce temperatures inside the home by as much as 8 to 10°F.

Deciduous trees provide summer shade, then drop their leaves in the fall. This allows the warmth of the sun to filter through their bare branches in winter and helps warm the home. If a home can be situated to take advantage of shade from existing trees on southeast and west exposures, energy expended to cool the house can be reduced.

If there are no existing trees, the owner can select and place trees that ultimately will provide shade. The temptation is to plant the fastest growing species available. However, this is usually a poor choice for several reasons. Trees that grow at more moderate rates usually live longer, are less likely to break in wind and ice storms, and are often more resistant to insects and diseases.

A carefully selected and planted tree with a moderate growth rate often will respond to good care by increasing its rate of growth. Recommended shade trees for North Carolina would include: Red Maple, Sugar Maple, Pecan, Birch, White Ash, Ginkgo, Honeylocust, Sweetgum, Tulip Poplar, Blackgum, Sycamore, White Oak, Red Oak, Willow Oak, Water Oak, Bald Cypress, Linden, Zelkova, River Birch, and Hickory.

Planting Tips and Precautions

The best time to plant is during the dormant season, Nov - Feb (tip...this is also when many go on sale). Summer is the worst time of year to plant trees as they need 1" of water per week.

For a healthier tree, mulch 2"-3" deep all the way to the drip line from the trunk but don't touch the trunk (however far the branches reach out, mulch the ground). Don't make your tree compete with your turf grass. Turf grass does not naturally grow beneath trees.

Avoid creating future problems when planting trees. Remember that a four foot tall, two foot wide tree might end up being 60 feet tall and 30 feet across. Learn the mature size and crown characteristics of any tree you buy and plant accordingly.

Plant trees far enough away from sidewalks, driveways, and buildings so the crown has room to develop. Full-crowned trees that naturally keep their branches all the way to the ground should be planted at least one-half of their mature crown width from any obstruction. Trees that can readily be pruned as they grow, like most deciduous trees, can be planted closer and allowed to overhang low obstructions.

Consider power line location when planting a tree. Trees that grow into power lines cause electrical outages and increased line maintenance costs. They also can end up in poor health because of the severe pruning that is sometimes necessary.

Wildfire hazard should also be considered when planning your landscape. In areas where grass, brush, or forest fires are likely, planting trees and shrubs near your home may not be appropriate. Contact your local fire department for more information on landscaping in fire-prone areas.