(Looking for a shorter read? Check out the “Shade is Money” Pictorial Guide HERE)
How to Save the Most Money from Trees in your Yard
Trees can save you real money! There are very few products in this world that can offer that kind of incentive. Sure, there are tons of other great reasons to plant a tree, but that summer power bill can really get you thinking about the almighty dollar. Not only can trees save you money, but it’s easy to get those returns if you know how to plant for energy conservation. Once you know how to pick the right trees and where to put them, the hard work is done. Most trees are very low maintenance, with little long-term upkeep required to keep them healthy for decades of savings. Read on to learn how bringing new green to the outside of your home, can keep more green on the inside of your wallet.
If you’ve ever sought the shade of a large tree to escape summer’s oppressive heat, you already know how trees will save you money. The sun is hot, and shade is not. The hot weather in North Florida lasts from 5-7 months each year, and almost all of us run the air conditioner that entire time. Approximately 50% of the energy used in a Florida home goes to maintaining interior comfort, and all that cooled air costs money. We save money anytime we can cool our homes without air conditioning, which reduces the amount of work our AC units have to do. AC units that work less also last longer, which translates to big savings when you consider a new unit can cost thousands of dollars.
So trees make shade, and we want that shade. How do you get those savings? Here’s how trees can help lower your heating and cooling bills to save you money.
———————————————————————————————————————————————————–
Blocking Summer Sun (Blocking Radiant Heating)
- When light from the sun encounters a surface it causes that surface to heat up, this is called radiant heating. The sun’s rays can come through your glass windows and doors to directly heat the insides of your home. Direct sunlight can also heat an outside wall, which then transfers that heat from the outside of the wall to the inside, by a process called conduction. Both processes allow direct sunlight to heat your home.
- You can reduce radiant heating by blocking direct sunlight with trees.
- Walls receive lots of hot summer sun, and benefit from being protected by shade. The most important walls to protect, in order of most to least important, are the West, East, and South.
- Windows account for a disproportionately large amount of radiant heating, as compared to the amount of area they occupy on a home’s exterior. Shading glass windows and doors from direct sunlight should be a primary concern.
- The closer a tree is to your home, the more shade it will cast on your house, and that shade will be present on your house longer.
- However, trees that are too close to the house can be dangerous and cause problems as they grow larger.
- In order to balance the costs and benefits of trees being close to a house, it is recommended they be planted 7-20 feet from the walls. Place smaller growing trees closer, and larger growing trees further back. Maximizing energy savings from shade trees will require tolerating some trees in relatively close proximity to the home.
- Choosing the sturdiest trees to plant near your home is the best way to ensure you have a long safe relationship with them. The University of Florida has done extensive field observations after multiple hurricanes and compiled lists of the most wind-resistant trees. We have included selections from these lists that are well suited for growing in North Florida. (see chart at bottom)
- Use deciduous trees for blocking summer sun on the east, west, and south sides of your house to get a second bonus in the winter (see Winter Radiant Heating Below for details).
- Shading your roof requires very large trees with overhanging branches. This can effectively reduce heat on the roof, but comes at the cost of danger from falling limbs. Proper attic insulation may be the more cost-effective way to limit heating from your roof.
- The path of the sun through the sky changes throughout the year. It crosses lower, toward the horizon in winter, and higher overhead in summer. These changes mean that the path of a tree’s shadow will change throughout the year. Casting shade on a small window from one small tree can be a challenge. Planting trees with wide spreading canopies will cast the largest shadows possible, making it easier to shade a target area.
- The shade cast by all trees is not equal. Pine trees cast a very light shade that does not block all of the sun’s direct rays, while Southern magnolias have very large thick leaves that block nearly all direct rays. Choose large leaved trees for the maximum benefits from shade.
Blocking Hot Summer Breezes*
- Undesirable outside air, entering a home through cracks in walls, windows, doors, and ceilings is called infiltration.
- Infiltration of hot air can be responsible for more heat gains inside a cool home than the radiant heating caused by the sun’s direct rays.
- In North Florida, summer breezes come from the south or southeast, and carry hot humid air that will heat the inside of your home if it finds entry points.
- Trees can function as wind blocks. The greatest wind protection from a tree occurs within a distance equal to 5 times the height of that tree.
- Trees to the south and southeast of a home can help block or slow hot breezes before they encounter our homes, which reduces the amount of hot air that forces its way inside.
- Use deciduous trees for blocking summer breezes, so you will get a second bonus in the winter (see Winter Radiant Heating Below for details).
- Less hot air forcing its way into your house, means less AC is needed to counteract it.
Evaporative Cooling
- The air above plants can be up to 9 degrees Fahrenheit cooler than bare ground.
- Water moves from the soil, through plants, and exits from the leave where it evaporates into the air.
- Water cools the air around it as it evaporates.
- More plants in an area means more evaporation, which means lower ambient temperatures.
- A yard full of plants will be cooler than one with fewer plants, so surround your home and landscape with plants for a dip in summer temperatures.
- Trees can help you save money in the winter as well, when we are spending cash to heat our homes instead of cooling them. As luck would have it, there is a whole category of trees that can do double duty by blocking sun in the summer while allowing it in during the winter.
Making Use of Winter Radiant Heating
- The sun’s direct rays work the same way in the winter as they do in the summer, by heating surfaces they encounter.
- The heat caused by direct sunlight is seen as a problem in the summer, yet this same effect becomes an asset in the winter.
- Deciduous trees have leaves in the spring, summer, and fall, but drop their leaves in the winter.
- Choose deciduous trees for east, west, and south placements near your house. Bare branches in the winter will allow the sun’s warm rays to strike your home and heat it, while the leaves protect the house from hot sun in the spring, summer, and fall.
Winter Wind Blocks
- In North Florida, in the winter, winds carrying cold air come from the north and northwest.
- As you spend money and energy to keep your home warm in the winter, you will benefit from keeping cold breezes away from your house.
- Trees planted to the north and northwest of your home will act as a windbreak to stop or slow cold winter winds before they reach your house, which will limit the amount of cold air infiltration.
- Use evergreen trees for this purpose, and plant them within a distance from the house that is equal to 5 times the eventual height of the trees.
- As you can see, there are a lot of ways that trees can help keep your house cooler in the summer and warmer in the winter. The details can get a bit complicated but the basics are simple.
———————————————————————————————————————————————————–
The Main Ideas
1) Keep warm summer breezes away from your cool house by planting deciduous trees off to the south of your home.
2) Create shade to block the sun’s hot summer rays by planting deciduous trees near the east, west, and south walls of your home. Those same trees will lose their leaves in the winter, allowing the warm sun to heat your home in the cooler months.
3) Plant evergreen trees to the north and north west of your home to act as windbreaks that will slow or stop cold breezes from chilling your warm house.
———————————————————————————————————————————————————–
Great North Florida Landscape Trees with the Highest Wind Resistance
Dahoon Holly – evergreen, native, great pollinator source in Spring, berries for birds in Fall
American Holly -evergreen, native, great pollinator source in Spring, berries for birds in Fall
Live Oak – evergreen, native, long lived trees support a bounty of wildlife
Bald Cypress – deciduous, native, fast growing upright trees
Crape Myrtle – deciduous, fast growing, summer blooms come in myriad of colors
Southern Magnolia – evergreen, native, classic symbol of the deep south, fragrant blooms
Sabal Palm – evergreen, native, state tree of Florida, pollinator and bird friendly
*Savannah Holly and East Palatka Holly are two easy-to-find evergreen trees that are both hybrids of the American Holly and the Dahoon Holly. While the UF observations of wind resistance do not specifically mention these two naturally occurring hybrid specimens, they share so many characteristics with their parent species that I believe it is safe and proper to include them on this list.
Great North Florida Landscape Trees with Medium-High Wind Resistance
Japanese Maple – deciduous, excellent focal point in a landscape, colorful options available
River Birch – deciduous, native, very fast growing…very fast!
Redbud – deciduous, native, pink to purple spring flowers
Native Fringe Tree – deciduous, native, creamy white spring blooms are a show stopper
Native Persimmon – deciduous, native, great wildlife food source
Japanese Magnolia – deciduous, stunning Spring flowers range from white to dark purple
Black Tupelo – deciduous, native, handsome landscape tree is well shaped, good Fall color
Chickasaw Plum – deciduous, native, great pollinator and wildlife food source
Winged Elm – deciduous, native, underused tree deserves more planting, very interesting bark
Other Evergreens for use as Windbreaks
Native Red Cedar – native, evergreen, fine texture foliage, good home for birds
Sweet Viburnum – evergreen, fast growing, if left untrimmed it will form a small tree up to 20’
Arizona Cypress – evergreen, versatile plants can be shaped and come in shades of blue
Other Small Trees
Crabapples – deciduous, Spring blooms and leaves come in various colors, wildlife food source
Fruit Trees – deciduous and evergreen options, money-saving shade and food from one source
Chinese Fringe Tree – deciduous, showy white blooms in Spring, plants can be easily shaped
Banana – deciduous, fast growing, adds a tropical feel for those who dream of the beach
Taiwan Cherry – deciduous, fast growing, produces the first blooms of the year in Tallahassee
———————————————————————————————————————————————————–
Planting New Trees
Starting off on the right foot is critical to success when growing plants. Check out our Tallahassee Nurseries video “How to Plant a Shrub” found HERE. Follow the same guidelines for planting trees.
Once you have properly planted your new trees in the ground, they will need water to stay healthy. Every location is different, and the unique soil situations of your particular planting spot will dictate whether you need to water more or less than the following guidelines.
As a rule, apply at least 1 gallon of water slowly and directly to the root ball every 2 days for the first Spring and Summer. Apply at least 1 gallon of water slowly and directly to the root ball every 4 days for the first Fall and Winter. Only rain over ¼ inch counts as a watering. The second year watering needs will reduce, water when leaves first show signs of wilting. Use at least double the amount of water each time for plants that start out in 7 gallon or large pots.
———————————————————————————————————————————————————–
*These suggestions are targeted at homes that use air conditioning. Homes without air conditioning should follow different planting advice designed to maximize their air flow.
———————————————————————————————————————————————————–
This article was written by Jonathan Burns (Tallahassee Nurseries Outdoor Manager, FNGLA Florida Certified Horticulture Professional) using information published by the University of Florida combined with years of personal observations growing in the Tallahassee area.
Sources
–http://ufdc.ufl.edu/IR00006188/00001
–http://ufdc.ufl.edu/IR00004807/00001
–http://edis.ifas.ufl.edu/fr273
–http://ufdc.ufl.edu/IR00004805/00001
–http://edis.ifas.ufl.edu/fr278