Shading your windows and roof is the surest way to reduce your air conditioner’s energy consumption. One of the best ways to shade the home is to strategically planted shade trees. At today’s electricity costs, it pays to buy a large tree (14-22 feet tall), costing $150 to $350, to shade the roof or windows. The tree’s type and where you plant it will determine how effectively it reduces your energy costs.
Tall trees with spreading canopies are the best sun blockers, when the sun is high in the sky. The sun is highest in the sky in the summer months and in the middle of the day. Plant these tall trees on the south side of your home 10 to 25 feet from the house to shade the south-facing windows and the roof. This will help prevent summer and midday sunlight from overheating the home. Tall trees will allow low-angle sunlight to hit the home in winter months when warmth is needed.
Broader, shorter trees are useful for blocking lower-angle sun. The sun is lower in the sky in the morning and evening during all seasons, and throughout the entire day in winter. Plant the broad trees 20 to 50 feet away from the east and west walls to block the morning and afternoon sun that tends to overheat a home during the summer months.
Tree planting is a very site-specific and climate-specific job. Discuss your tree planting plans with your local nursery’s tree specialist or a local landscape architect. Investigate tree characteristics such as watering needs, required levels of clean-up (fruit, flowers, and leaves, for example) and whether the tree roots may clog nearby drain pipes.
Trees on the South should overhang the roof. Trees on the East and West should block the sun coming from a low angle.
The way you plant a tree is very important to its health and growth rate. Investigate the soil at your tree-planting site. Loosen the soil at your planting site to a depth of at least a foot and then remove it. Follow your tree expert’s recommendations for adding organic matter or fertilizer if necessary. When trees shade your yard, the yard needs less watering and the air around your home is cooler. So, when Spring comes around, plant a tree!