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57 Ways To Protect Your Home Environment (and Yourself)
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56. Use Plants And Other Landscape Tools To Conserve Energy
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What you plant and where you plant outside your home can have a major impact on the amount of energy you use to heat and cool the inside of your home. The goal is to block summer sun and winter winds and to allow access to winter sun and summer breezes.

In the summer, the sun rises in the northeast and sets in the northwest. In the morning, the sun’s rays are almost perpendicular to the east wall, so there is maximum heat absorption. However, the air and the house are not heated significantly because of the cooling that took place overnight. For this reason, tree plantings are probably not necessary to shade the east wall.
summer sun at noon hits south wall from high angle

 The south wall receives full radiation between 11 a.m. and noon, but the sun hits the wall at such a steep angle that the amount of heat absorbed is much less than might be expected. In general, the use of trees to shade the south wall is not effective because the shadow cast is minimal. A roof overhang does a much better job.
shaded house

 For most of the afternoon, the west wall receives the same exposure that the east wall did earlier. However, now the sun is at maximum heating capacity, the air is hot, and the house has lost its coolness. If there is space for only one tree to protect the west wall, place it up to 25 feet from the house on a line between the 3 p.m. and 5 p.m. sun positions.
winter sun at noon hits south wall from low angle

 In the winter, sunrise is in the southeast and sunset in the southwest. The south wall receives nearly all of the winter’s day sun. If you plant a tree on the south wall, make sure it is a deciduous tree, which loses its leaves in the fall. The sun can shine through the leafless branches during the winter.
fenced yard

 Trees and plants are commonly thought of as the only way to intercept wind, but fences also work well. Fences require less ground space and provide immediate protection. Be sure your fence has slats. Solid fences make the wind more vicious. If you choose plants to protect against winter wind, use evergreens because deciduous plants have no leaves during winter.
windbreak proctection

 To determine how much protection you can get from a windbreak, multiply the windbreak’s height by 20. This means that a 10-foot-high windbreak will give you a zone of protection of 200 feet (10 x 20 = 200 feet).
shrubs at entryway

 Windows and entryways are prime sources for heat loss or gain. A baffle fence or courtyard development with small trees and shrubs can help. A home with exterior walls that include a projection or recessed area can be highly vulnerable to wind and air filtration. Fences or plantings can reduce these problems.
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