Planting trees for savings and conservation

by William R. Scott, City Forester
Thursday, February 28, 2008 10:06 AM MST

Homeowners go to great lengths to conserve energy in this era of tight budgets and environmental awareness.

Many, however, do not realize that the simple act of planting a tree can result in energy savings.

The right tree 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 other obstacles in the landscape.

So what is the right tree?

Deciduous trees save energy in summer by shading houses, paved areas and air conditioners, evaporative coolers and decks and patios. Small deciduous trees and shrubs, and especially those with low, dense branches, also can serve as effective wind barriers year-round.

Large and small evergreen trees and shrubs save energy by slowing cold winds in the winter. They also provide shade, but since they often have branches near the ground, their shade is most effective when the sun is not directly overhead.

Deciduous and evergreen trees save energy in summer by directly cooling the air. This cooling happens as water evaporates from the leaf surfaces.

What is the right place for shade?

Shade from trees reduces air conditioning needs and makes non-air conditioned homes more comfortable.

Plant deciduous trees so that they will shade south and west-facing walls and windows during June, July and August. Trees with mature heights of at least 25 feet should be planted south and west of the house.

Plant smaller deciduous or evergreen trees with lower limbs east, northeast and southwest of the building to provide late afternoon and early morning shade.

Larger deciduous trees planted to the east, north or northeast will only shade a building in the summer if they extend out over the roof.

In the winter, when maximum sun is desired, such trees will provide too much shade. Even deciduous trees that have dropped their leaves cast quite a bit of shade in the winter.

Take into consideration the mature size of your trees to avoid conflict between buildings, utilities and property lines.

What is the right place for wind protection?

Especially important in Wyoming is protection from winter winds. Trees can reduce energy use by blocking cold winter winds that enter homes through small openings and also carry heat away from the building's outer surfaces.

Effective windbreak trees have crowns that extend to the ground and branches that keep their foliage in winter. Junipers, spruces, pines, firs and evergreen shrubs are good choices for wind protection.

Trees for winter wind protection should be planted upwind of the area to be protected.

Windbreak trees can be planted in straight or curved rows or in groups. They should be close enough together so that their crown edges meet within a few years without overcrowding. Wind protection extends downwind 10-20 times the windbreak height; therefore, the trees need not be planted close to homes or buildings to be effective.

Keep in mind that snow drifting will be the worst at two to three times the windbreak height downwind.

What precautions should I take?

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, utilities and buildings so that the crown has room to develop without becoming a nuisance.

Wildfire hazard also should 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.

Planted properly, trees can save money and energy, enhance your landscape, increase the value of your property and improve quality of life for you, your family and your community.

For questions about your trees, contact the City of Casper, Urban Forestry Section at 235-8309 or send e-mail to wscott@cityofcasperwy.com.

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