Energy Efficient Landscaping
Physical modifications to your home or property are not the only way to improve efficiency. If you can modify your yard, investing in landscaping can be a cost-effective way to help heat and cool your home. Carefully positioned trees and shrubs can save up to 25% of the energy a typical household uses by providing strategic windbreaks and allowing for shade and sun.
In energy-efficient landscaping, the goals for the property are determined by its climate zone and microclimate. Broadly, West Virginia generally falls within the cool climate zone, while Maryland has a temperate climate; however, a property can have multiple microclimates. You can use this form developed by the UC Master Gardeners to assess what the microclimates are for you.
Note: Cool and Temperate Climates: The main landscaping goals for properties in cool and temperate regions should be to get as much sun as possible in southern-facing windows throughout the winter, shade south and western windows in the summer, and create windbreaks.
Landscaping for Windbreaks
Windbreaks reduce heating costs by preventing wind chills near your home and can be especially helpful for older homes that are less insulated. Well-chosen landscaping can also insulate your home by creating dead airspace to keep it in climate-controlled air throughout the seasons.
To effectively block Winter Winds, plant evergreen trees and shrubs to the north and Northwest of your property. These trees should be placed at distances two to five times the tree's height once fully grown. If you live in an area where snow drifts pile up, you can also plant shrubs to block the snow before it reaches your home. The Arbor Day Foundation Tree Wizard can help you choose the best trees for your area.
Landscaping for Shade
In cooler climates, shade in summer may not be a necessity. However, depending on the specific needs of the property owner and its occupants, added shading plants may still improve energy efficiency. Cool air settles low to the ground in the space underneath the trees. It can be up to 25° F cooler than air over a black top when placed over a roof or in front of exterior walls. Energy-efficient Landscaping can cut summer air conditioning costs by 15% to 50% and can return your investment in less than eight years. In addition to passively cooling your home, cool air from the shade helps air conditioners run more efficiently.
To effectively plant for shade, you must note where you have existing shadows and Sun throughout the hottest parts of the year since Shadows can fluctuate year-round. Start with Western windows and walls and then move on to the Eastern side of the property if necessary. Do not plant trees to the south of your property. The summer sun will often cast a shadow directly down, not over your property. In the winter, a southern tree may undesirably shade your home and reduce air temperature.
Plant trees within 20 feet of the building but far enough away that the root system does not grow to disturb your property’s foundation. The trees ideally should grow 10 feet taller than your highest window. When choosing your trees, consider what will grow best in your region and microclimate. Deciduous trees will be full in the summer and provide excellent summer shade but will also die back in the winter to allow for warming sunlight. In contrast, evergreen trees will provide year-round shade and may not be a good option for properties in cooler climates. Climbing vines or high shrubs are another effective plan to use in addition to or instead of trees; however, avoid planting vines and plants in direct contact with the exterior of a building, where increased moisture may pose an issue.
Note: Planting shade trees is an excellent way to reduce the amount of solar heat absorbed through your roof. However, if you have or plan to install rooftop solar panels, carefully consider the placement of your landscaping to avoid shading these areas.
Landscaping for Sun
As with shade in the summer, it is important to let as much solar heat as possible reach your home during the cooler months. Prune lower branches off southwest or southeastern trees to allow for the most possible sunlight while receiving the full benefit of mature landscaping. If you live in a cool or temperate climate, always choose deciduous trees to the west and east of your property to ensure that the foliage will drop and allow light in through winter.
Native plants
When landscaping, try to focus on protecting existing trees which where often planted with optimal sun or shade in mind decades before. New plants should ideally be native species that are already well-adapted to the climate and microclimate of your property and will enhance its historic beauty. You can use the West Virginia Planting Tool to help you select the ideal plants for your location, or visit the West Virginia Native Plant Society’s resource page for more information. Always avoid invasive ornamental plants, such as honeysuckle, English ivy, and Lesser Periwinkle, which may spread and cause damage to exterior walls if allowed to climb and suffocate surrounding plants. Once established, invasives can be expensive and difficult to eradicate.
