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.
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.
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.
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 it leaves in the all. The sun can shine through the leafless branches during the winter.
Other medium sized trees that can be planted are East Palatka or Eagleston Holly, Little Gem Magnolia, Japanese Loquat, Ligustrum, Weeping Yaupon Holly, Cherry Laurel, Bottlebrush, Japanese Blueberry and Fruit trees.