Especially in this time of inflation and rising energy costs, heating and air conditioning can take a big chunk out of the household budget. Of course, you can lower (or raise) your thermostat, add insulation to doors and windows, install thermal windows, and close off unused rooms, but there are other, indirect ways to reduce household energy consumption. One strategy to trim the fat off energy bills is the use of environmentally-friendly eco-landscaping.
In 1985, my family moved to a small farm in Sharpsburg, Maryland. The wooden-frame house was built sometime around the turn of the 20th century, and I’m guessing it was about this time that the owners planted sugar maple trees around the front and sides of the house. We moved there in August when the daytime temps were in the 90s, yet there was no need for air conditioning. The large canopies of the maple trees blocked the sunlight and kept the house cool all summer.
(We were sad to lose one of the maples to a lightning strike one summer, and years later, we lost another one that had begun to crack and break up from old age. The trunk on that one was as wide as our front door, and some of the lower limbs were a foot in diameter. We got several cords of firewood out of the wood, which kept our wood stove fed for a couple of winters.)
A good landscaping plan can make a home significantly more energy-efficient. Strategically placed trees and shrubs can do double duty, providing cooling shade in summer and insulation against heat loss in winter. According to the U.S Department of Energy, properly selected, placed, and maintained landscaping can reduce household energy bills by as much as 25 percent. While landscaping can involve a significant expenditure up front, it will pay for itself over the long haul in lower energy bills.
Landscaping strategies for conserving energy depend largely on where you live. The USDA Plant Hardiness Zone Map, shown below, divides North America into 11 planting zones to help homeowners determine the best landscaping choices for their region. Each growing zone is 10°F warmer (or colder) in an average winter than the adjacent zone. If you see a recommended hardiness zone in a gardening catalog or plant description, chances are it refers to this map.
Create an Effective Windbreak to Reduce Winter Heating Costs
Landscape windbreaks, such as a row of trees or a hedge, are commonly dense evergreen trees and shrubs. A row or hedge of evergreens is preferable to deciduous trees for blocking the wind because their mature heights in relation to typical home heights are ideal for wind blockage. They are also dense enough to stop most of the wind and have foliage that extends to the ground. In addition to planting banks of large trees and shrubs, planting smaller shrubs next to a home further reduces the impact of wind. The figure below illustrates a typical plan for windbreaks.
Plant Deciduous Trees Around the House to Reduce Summer Cooling Costs
When the summer sun beats down on your home, blasting the air conditioner or running ceiling fans are the only ways to cool your house. Fans don’t use much electricity, particularly if set to a low speed, but they just move the air around rather than cool it. Air conditioning, on the other hand, uses a lot of electricity. If you’re like me and want to run the air conditioning as little as possible, a good landscaping plan can, over time, help to lower summer cooling costs. The cooling provided by an even partially-shaded house means a lower energy footprint and more green in your wallet.
Trees planted on the west and south sides of the house provide the greatest savings since they provide shade from the afternoon’s hottest summer sunlight. Deciduous trees are better than non-deciduous (evergreens) trees, as they will lose their leaves in the fall and allow what sunshine there is to effectively do the opposite and provide more warmth to the home. Be sure to plant trees that are tall enough to shade the roof, windows, and walls for the months of June, July, and August.
The ideal shade tree is 25- to 50-feet tall with a big canopy. A tree that size will partially shade the roof of a one-story home, but will not reach an unmanageable size. As a general rule of thumb, large trees should not be placed closer than 15 feet from the foundation so the roots won’t cause a problem with the foundation. Keep in mind how big the trees will get at maturity so they will be properly spaced and provide the desired shade.
Smaller trees and shrubs also have a role to play in energy conservation. They can be planted closer to the house than tall trees to shade east- and west-facing walls and windows in the morning and afternoon when the sun is lower. Spreading evergreen shrubs with dense foliage, such as yews or junipers, planted close to the house, can fill in rapidly to shade walls and windows (as a bonus, these shrubs can provide sheltering places for birds in harsh weather or a quick place to hide from aerial predators.) In wet and humid areas, avoid planting up against the house so air can circulate freely. Check with your local extension office or garden center before buying a landscape shrub for advice on species that are invasive or prone to serious pest or disease problems in your area.
The high cost of home heating and air conditioning is pushing more homeowners to explore ways to reduce home energy use. Outdoor landscape plants—which help control erosion and are pleasing in themselves—can play a large part in controlling household energy use. For that reason, it’s important to consider the entire landscape plan in relation to energy conservation on the homestead.