I have a large shade tree on the south side of my property that keeps the summer sun off of my mobile home. This shade tree makes such a big difference that I rarely need air conditioning. It's a large cedar, but any fast growing tree will work. If you plant a tree that looses it's leaves in the fall, then you'll still get the benefit of winter sunshine to help heat your home!
By Cyinda from near Seattle
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According to the Department of Energy, strategic planting of as few as three trees can provide the average household with an energy savings of between $100-$250 annually. It may be the best long-term investment for reducing heating and cooling costs.