The writer is a member of the Cornell Cooperative Extension of Albany County.
I generally begin thinking about home energy consumption around this time of each year. Is it going to be a cold winter? What is the cost of fuel? How much am I likely to burn this year? I don’t have a good answer to any these questions so I continue to worry. One way I know I can impact my home energy us is through the way I plan and design the landscape around my home. Proper plant selection and placement will allow me to cut down on energy use in the winter and in the summer.
Designing a nice landscape is aesthetically pleasing but can also be very functional in reducing home heating costs in the winter and air conditioning cost in the summer. Cold winds out of the north and northwest can be slowed and diverted by a properly design landscape. A windbreak can be designed reduce your winter fuel consumption from 10 to 25 percent. A living windbreak should be sited on the north and northwestern side of the home. The most effective design is to place plant material in a U or L shape and extend the planting, if property allows, well beyond the corners of the house. How far away should this windbreak be located? It depends on the plants you select. The maximum wind protection is going to occur at 4 to 6 times the height of the trees. A twenty foot tall evergreen windbreak will provide the greatest reduction in wind 80 to 120 feet to the south and southeast. So, the size of your property will impact the plant material you are able to select.
What plants are best to use. If you only have space for a single row of trees, an evergreen pine fir, spruce, hemlock or arborvitae would be your best choice. Space these rather close, 6-8 feet apart, stagger them if have room to plant multiple rows. If you have the space multiple rows of plants of varying species will provide the best wind break. You should plant the rows 12 to 20 feet apart. A mixture of taller deciduous trees combined with shorter evergreen trees and shrubs will provide the best protection. Keep in mind that windbreaks need to allow some wind to penetrate. If they are too dense, a partial vacuum could be created and thereby reduce their overall effectiveness. The windbreak functions by reducing the air movement around the home and thereby slowing the loss of heat from the structure.
Foundation plantings also help reduce heat loss from the walls of the home by creating a dead air space against the structure. Evergreen shrubs in particular are very effective in diverting wind and protecting the foundation. The most effective insulating affect comes from a continuous planting along the entire foundation. Rhododendron, holly, yews, junipers, and assorted dwarf conifers are all acceptable plant materials. Deciduous plants are also helpful, especially those woody plants that are not cut back until spring. This insulating affect is desirable in the summer months as well.
Summer cooling can be achieved by the selection and placement of medium to large deciduous trees on the south and southwest side of the home. To provide shade to the roof of a single story home a large tree can be placed 20 feet from the house. Medium sized trees can be placed up to 15 feet from the home. The leaves will intercept the sunrays and provide shade in the summer and the leafless branches will allow the warmth of the sun to penetrate in the winter.
Using trees to shade paved surfaces such as driveways also reduce temperatures around the home. The evaporative cooling effect of the water vapor passing through the leaves of the tree can reduce temperatures under the tree up to 9 degrees Fahrenheit. Shade trees not only enhance the beauty of the landscape they can provide comfort and reduce energy consumption. For more information about selecting plants for your particular location, contact your local Cornell Cooperative Extension office.