Energy Saving Planting

Recent studies have shown that selective, well-planned landscape plantings can significantly reduce wind velocity, thereby reducing heat loss from homes and saving you money on fuel costs. Trees can also help you cut air conditioning costs by cooling your home in the summer. There are some simple guidelines for preserving beauty and conserving energy at the same time.

Winter Saving

The location of a windbreak is essential to its ability to shelter the house and cut fuel consumption. Since prevailing winter winds come from the north and west in most parts of the U.S., windbreaks are usually most effective on these sides of a house. Generally, savings from windbreaks increase as the protected perimeter of a house increases. Yet, only a few well-placed conifers will make a difference if your house is currently exposed.

We suggest that, where possible, windbreaks on the east or west be planted about 50 feet from a house. On the north side of your home, closer windbreaks will probably be more efficient. If local wind conditions warrant placement of windbreaks on the south side of a house, they must be farther from the house, to prevent winter shading.

Any conifer will provide effective wind protection, but in general, choose fast-growing, visually dense species with stiff branches. (Of course, you must first check which species grow best in your area.) Norway, white, and Colorado blue spruce are among the best windbreak trees; blue spruce usually provides the most protection, but is slower-growing than the others. Whichever species you choose, a fast-growing variety or cultivar will begin saving fuel costs more quickly. Although single-row conifer windbreaks are quite suitable, the effectiveness of a windbreak generally increases with each added row, up to about five rows. However, with dense trees such as spruce, one or two rows is probably the most cost-effective windbreak.

The spacing of trees within a windbreak depends in part upon the species used. For narrow windbreaks, pine and spruce should be placed about 6 feet apart in the rows. Cedar and arborvitae should be about 3 or 4 feet apart. The rows themselves should be roughly 10 to 12 feet apart. Trees in the rows should be staggered in relation to the trees in adjacent rows.

A landscape plan for a half-acre home site with prevailing winter winds from the northwest and summer breezes from a southerly direction in a temperate portion of the country would incorporate coniferous windbreaks to protect the directions where the strongest winter winds come from and trees on the east and west sides to provide summer shade.

The year-round effect of foundation plantings seems never to have been measured, but the authors would expect them to be energy savers if they do not shade windows in winter.

One very important note: don't prune the lower branches from windbreak trees. Trees so pruned can actually increase wind speed near the ground rather than reduce it. Another caution: a dense single-row windbreak can cause nuisance snowdrifts if it is just upwind of a driveway or sidewalk.

IT PAYS TO SAVE

Reprinted with permission of the Urban Forestry Program of the American Forestry Association.