By Steve Cramer, Horticulture Agent, Colorado State University Cooperative Extension
If you are concerned about rising energy costs proper landscaping could make a significant difference in what you are paying to heat and cool your home. Through proper use of trees, shrubs, vines and man-made structures, you can modify the climate around a home to reduce heat gains in summer and heat losses in winter.
You will use less energy because you will be protecting your home from winter wind and shading it from summer sunlight. Using various techniques, winter heating bills could be reduced by as much as 25 percent and summer cooling bills could be reduced 50 percent or more.
The recommended way to provide shade is to plant deciduous trees in an arc around the home on its east, south, southwest and west sides. When planting shade trees, locate them with an understanding of their mature height. This way, they will be properly spaced and still provide the desired shade.
Location of shade trees also depends upon the shape of the tree crown, the position of the sun, height of the roof or walls, keeping a desirable distance from windows, aesthetic appeal in landscaping a home and avoiding overhead wires and underground pipes. A tree that is a small twig when planted can grow into a large tree at maturity. If you do not plan for the mature height and shape of the tree in advance, its location can cause problems.
Wind is the other important climatic element to be controlled. Research conducted on the Great Plains has shown that up to 25% energy savings for heating is possible by using windbreaks. An evergreen, properly placed, can divert cold winds away from the home in the direction of the prevailing winter wind, Using this as a guide, you will generally locate the windbreak to protect the north and west sides of the home.
Extra evergreens planted close to the home can further reduce effects of wind. If allowed to develop into a thick hedge, planting spreading evergreens in front of the north and east wall will provide additional insulation because of the trapped dead air space created. If an entry is exposed to wind, an evergreen planting to shelter the entry will be effective.
Use fences, windbreak plantings and shade trees to provide a sun pocket on the south side of your home where outside activities can take place during our sunny, cool but comfortable winter days. A sun pocket would make an excellent location for a patio or greenhouse.
Observe the sun during different seasons of the year. Notice how the sun strikes the house between 9 a.m. and 3 p.m. in the winter. A south-facing solar heating device (including a window) receives the majority of its solar radiation between these hours during winter months. Notice also how the sun strikes the house during the summer months, particularly in early morning and late afternoon, so that appropriate shading can be provided.
Add shade trees to your plan to maximize summer shading and winter solar heating. Choose specific trees for your plan with an understanding of their mature height. This will determine where they should be located for maximum effectiveness. Choose vines and shrubs in a similar fashion. Add man-made structures appropriate for immediate effectiveness.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010