How to Slash Your Home Energy Use Through Strategic Gardening

Heating and cooling our homes eats up plenty of energy. Reduce the load with native plants that block summer sun or winter winds.

Editor's note: Want a climate-friendly home? Your yard is a good place to start. This is the third in a five-part series of guides on how to manage your outdoor turf to reduce your carbon footprint, all while creating bird-friendly habitat. Read one, two, four, and five.

A well-designed yard can pack big climate benefits outside of your home—and also inside it, too. 

Acccording to the U.S. Energy Information Administration, residences generate more than 21 percent of the country’s total climate emissions. “Our houses are a major factor in climate change because of the energy used to build and operate them,” says Ellen Larson Vaughan, policy director for high-performance green buildings at the Environmental and Energy Study Institute. A big portion of these emissions are linked to heating, cooling, and ventilation, which account on average for about half of home energy use.

By strategically placing trees, shrubs, and vines to block blustery winter winds or create shade, you can slash the amount of fossil fuels required to heat and cool your house and dramatically reduce your climate footprint. As a bonus, you’ll put a dent in your utility bills.

To maximize your yard or garden's climate potential, consider the following tips.

What’s Your Climatic Zone?

Which landscaping strategies will make most sense depends on where you live. A U.S. Department of Energy map divides the country into four climatic zones—cool, temperate, hot and arid, and hot and humid—and an accompanying list prioritizes the three most effective actions for each region.

If you live in the cool zone, which includes the Northern Plains and Midwestern states and northern New England, it makes sense to create windbreaks to insulate your house from winter cold and to make sure no evergreen trees block the sun from reaching south-facing windows. If you’re from a hot and arid zone, your best bet is to shade your roof, walls, and windows. Making the most of summer shade as well as directing cooling breezes toward your house are the most important actions to take in the hot and humid region, while residents of the temperate zone should take advantage of the sun's warming effects in winter and cooling shade in summer.

Made for Shade

As the sun beats down on your house, a huge amount of heat can be absorbed through your roof and windows. However, some smartly located plants can conserve energy and curtail greenhouse gas emissions while reducing your air conditioning costs by 15 to 50 percent.

Where overheating is a year-round problem, use evergreens to provide continuous shade. If you reside in a temperate region, employ deciduous plants, which lose their leaves when cold weather arrives, to block solar heat in summer but let it in during the winter. Wherever you live, be sure to avoid shading any solar panels on your roof.

A few easy ways to shade your house include:

• For quick results, plant shrubs or small trees to shade east- and west-facing windows in the morning and late afternoon when the sun is low in the sky and solar heat can directly penetrate.

• Alternatively, plant vines that will quickly clamber up a trellis or other support. Permanent structures like wooden lattice trellises are most appropriate in hot climates where preventing solar heat gain in winter isn't a problem. 

• Large trees and shrubs take longer to fill in but ultimately provide the most extensive shade. Trees can reduce summer temperatures significantly, especially when they’re located on the south and west sides of your house. A six- to eight-foot deciduous tree planted near your home will begin shading your windows right away. Depending on the tree species and the height of your house, it will shade the roof in five to ten years.

Warding Off Winter Winds

As anyone who has tuned into a winter weather report knows, wind chill makes cold significantly worse. However, it is possible to keep your house warmer, conserve energy, and reduce your carbon footprint by planting a windbreak—a band of evergreen trees and shrubs located perpendicular to the prevailing winds. In a study done in South Dakota, windbreaks cut home fuel consumption by an average of 40 percent. They also, of course, provide habitat for both breeding and migrating birds.

To create a windbreak with maximum protection, plant at a distance from your house of two to five times the mature height of the trees. Use species that have branches close to the ground, such as native spruces and firs, or plant trees and shrubs together to impede wind gusts from ground level to the treetops. On small city or suburban lots, a dense evergreen hedge planted perpendicular to the prevailing winds several feet away from the house can help keep it warmer in winter.

Capturing Breezes

You can also apply wind-shaping principles to keep your home cool. To direct breezes toward your house, plant a hedge parallel to the prevailing summer winds, in a funnel shape that is wider away from the house and narrower close up. The hedge will not only enhance the breeze but can force cooling air through your windows.

Whatever your goals, remember that all of these tips are heavily dependent on what’s right for where you live. For details on creating an energy-conserving landscape in your area, contact your county’s Cooperative Extension office. And to select the most bird-friendly trees, shrubs, and vines, consult Audubon’s native plant database.