Lower Your Electric Bill by Careful Placement of Plants
Carolyn Saft, Multi-County Horticulture & FYN Agent
Are your electric bills making you
sweat more than the summer heat?
April to November, sunlight intensities
elevate air temperatures far above the human comfort level. In Florida, about 35 percent of our annual residential energy expense is for cooling homes during Florida's five-to-seven- month long summer. Even though we can’t change the weather, we can create landscapes
to cast shade, channel winds and reduce temperatures near our homes. Our unique climate provides many opportunities for using landscape materials to moderate the home environment and actually reduce monthly utility bills by as much as 30 percent. You can lower those bills by planting the right plants in the right place.
We can begin by making a list of specific problem areas we would like to correct. Does our house have particular windows that need to be shaded? Glass windows and doors can account for between 30 and 60 percent of a building's total heat gain by providing the most direct entry for heat into our homes during the summer. Consequently, special attention may need to be given to walls containing the most windows and glass doors and especially those with west or east exposures. Is humidity a problem around one side of your home? Would you enjoy your backyard more if there was more shade or wind movement? An area that is shaded can create a dramatic effect by dropping ground temperatures by 3-6 degrees in only five minutes. Let's take a look at some planning ideas.
Shading with trees:
The shape of the tree influences the duration of the shade. Round or vase-shaped trees and spreading tree canopies provide
shade longer than columnar, oval or pyramidal canopies. Trees like Red Maple, Fringe Tree, American Hornbeam Redbud, Loquat, Sweetbay, Bradford Pear and Winged Elm are all suited for shading houses. Small to medium size trees should be planted at least 10 feet from the house and larger trees should be planted even further away. This is because tree limbs over the roof can present a nuisance from plant debris clogging rain gutters, staining roof tiles, or even cause wearing of roof surfaces from rubbing branches. In addition, there is a risk of injury or damage if heavy limbs fall off in an afternoon thunderstorm or during tropical storms. Selecting deciduous trees will help warm your home in the winter if that is something you need to help with energy costs. Of the above trees only Loquat and Sweetbay are evergreen; so they do not lose their leaves in winter.
Mature tree height should also be considered when selecting plants. Generally, small or medium sized trees (26 to 30 feet tall) are preferred for shading walls. If taller trees are selected, they should be planted further away from the house so they don't become a safety hazard. Be wary of fast growing trees that increase in height by three feet or more per year. Most fast growing trees are short-lived and week-wooded, two undesirable characteristics because they break apart in high winds.
Managing breezes with landscaping is a very effective means of controlling indoor home temperatures. A common mistake we make is channeling summer breezes toward our homes. This technique was used years ago before the use of central air conditioning.