University of Florida

Enviroscaping


Shrubs, trees, and groundcovers can reduce cooling costs and make your home more environmentally friendly.

Introduction

Historically, landscaping has been used as a tool to modify the home environment. Before mechanical heating and cooling systems were invented, humans depended on being able to change their surroundings to better suit their needs.

In attempts to combat Florida’s hot climate, early settlers created open homes and used trees and other landscapes to channel tropical winds. People welcomed the cooling breezes because it helped relieved the sweltering heat.

Florida Climate

Sunlight

Sunlight generates Florida's consistently warm temperatures. During the hottest months of April through November, the intense sunlight can make the air temperatures nearly unbearable.

Humidity

Since Florida is a peninsula, it receives moist ocean breezes. Tropical air heated by the sun sweeps off the Gulf Mexico and creates a hot, humid climate. Florida also receives about 54 inches of rain per year, which increases the humidity levels.

Winds

Fortunately for most of the year, winds act as a natural fan across most of Florida. While coastal areas are relieved with ocean breezes daily, inland areas create ways to direct and enhance winds.

Getting Started

From the hilly regions in the northern Florida to the tropical Keys, Florida provides many unique landscaping opportunities to control the home environment, creating a more comfortable home environment and reducing utility bills.

Most residents constantly try to find ways to keep the heat out and lower inside humidity. Trees, shrubs, grasses, and other groundcovers can be highly effective in controlling these elements when combined with planting strategies specific to Florida's hot humid climate.

As a homeowner, you should start by making a list of specific problems you would like to correct. Ask yourself the following questions, so your landscape design can be tailored to meet your specific needs.

Does your house have particular windows that need to be shaded?

Is humidity a problem on one side of your home? Encouraging wind movement could make that area of your yard more usable.

Is your home passively cooled (no air conditioning)? Houses that are passively cooled will require different landscape techniques than a home that uses air conditioning.

Although you can’t control the weather, you can channel winds, cast shade, and reduce moisture near your home. Modifying these forces can create more comfortable living conditions and can lower your utility costs as much as 30%.

Using Shade to Reduce Temperatures

When shaded, ground temperatures were found to drop an average of 3°F–6°F in only five minutes. Studies have also shown that temperatures on a forest floor can be as much as 25°F cooler than those recorded at the tree tops.

Shade can also drastically affect home comfort levels and energy costs. Creative landscape planning with trees, shrubs, and vines will help alter the climate outside your home and modify indoor temperatures.

Trees

Observe which windows receive the most sun in your home to determine the best place to plant shade trees. Since windows and walls facing east and west receive about 50% more sun than those facing north and south during warmer months, they should be your top priority.

During design planning, note that trees are more effective at shading when planted close to the home. A tree planted 10 feet from the west wall will shade an area four times longer than a tree planted 20 feet away.  Also, take advantage of the tree’s shape to get the greatest amount of shade—spreading, round, and vase-shaped tree canopies provide the best shade for the longest time.

Consider mature tree height when selecting plants as well. In general, small- or medium-sized trees (26–30 feet) are preferred for shading sidewalls. Taller trees should be planted farther away from the home because they can become a safety hazard when canopies begin to overhang the roof.

During the summer months, deciduous trees have a full canopy of leaves that provide shade. In the winter months, they drop their leaves, allowing the warming effect of the sun to filter through. In general, the south and southeast sides of your home are the best locations for deciduous vines, shrubs, and trees. Northern Florida is known to have winters with temperatures below freezing and having deciduous plants near you house can reduce how much you'll need to run the heater.

Shrubs & Vines

Shrubs are also useful for shading your home. When planted a few feet away from the house, they can provide extra shade and control humidity without obstructing air flow. Since trellised vines can grow in more confined places than trees or shrubs, use them to shade windows where space is limited. Evergreen vines are a good choice for providing shade along the east and west sides of the house. To take advantage of the winter sun, deciduous vines—such as wisteria—should be planted on southern exposures.

Air Conditioning Units

To keep air conditioning costs to a minimum, shade the outside condensing unit. Make sure to have sufficient room for air to move around the condenser, so it can operate at its peak efficiency.

Channeling Wind to Your Advantage

Wind channeling is a popular landscape technique to save energy. Landscaping can manage effectively manage breezes to control indoor home temperatures during both winter and summer months. By using trees, shrubs, vines, and other vegetation, you can alter the direction of wind near your home.

While passively cooled houses should be landscaped to direct breezes into the home, mechanically cooled homes need windbreaks to control summer breezes and to keep utility costs low.

Passively Cooled Homes

Cooling breezes are greatly welcomed in Florida's passively cooled homes. Houses that use minimal or no air conditioning should direct wind toward windows and screened doors for cross ventilation. Operable windows should be positioned opposite each other on the north and south walls.

Place shade plants far enough away from the house, so they do not restrict air flow. Also, avoid using low-branching trees on the southeastern or southwestern exposures.

Homes Designed for Mechanical Cooling

During Florida’s long and hot summers, many residents find it nearly impossible to stay cool without air conditioning. To keep your air condition costs to a minimum, consider outside air infiltration.

Humid air that enters your home through windows, doors, and other structural cracks can increase your energy costs.  Positioning plants, shrubs, and trees around these areas will help slow and reduce the amount of warm air entering your home.  The more dense and closed a shrub is, the more the wind is slowed.

To determine the best places for your vegetation, observe a wind sock or a similar device for several days in the winter and summer. Once prevailing winds are determined, landscape planning will be easy.

Cooling with Groundcovers

During the summer, you can often see heat waves rising from sunbaked streets and parking lots. Paved areas store the sun’s heat and radiate it back into the environment immediately. Planting groundcovers around paved surfaces at your home can help reduce temperatures and combat the summer heat.

Groundcovers are low-growing plants that can be used to cover an area in the landscape. Turfgrass—the most common groundcover—can withstand more foot traffic than any other plant material. However, turfgrass does not grow well in areas that are extremely wet, dry, or heavily shaded. Fortunately, there are other groundcover alternatives that can provide more cooling than mowed grass.

Native plants to Florida, such as sword fern, railroad vine, coontie, and sunshine mimosa, can all be used as groundcover options.

Groundcovers can create a more beautiful, colorful, and comfortable home environment and add a unified element to your lawn.

Low-energy Landscape Practices

Most residents prefer a lush landscape bordered by a carpet of green lawn. However, many homeowners often overuse fertilizers, pesticides, and water to achieve their desired landscape. This results in accelerated plant growth and requires more frequent pruning, mowing, and general cleanup.

Fertilizers & Pesticides

Although it’s tempting to use fertilizers and pesticides excessively, a healthy landscape can be created by following a planned maintenance program with moderate fertilizer and pesticide use. Too much fertilization can contribute to groundwater contamination, waste valuable energy, and require more human effort.   

Water & Irrigation

The amount of water a plant receives also affects its growth. Overwatering and high fertilization rates can lead to rapid growth, contributing to insect and disease problems. It’s best to use sustainable irrigation practices, such as micro-irrigation, or use drought-tolerant plants to help save water.

Yard Waste

Many homeowners throw away their grass clippings, but it’s actually best to leave them on the lawn to decompose. This will naturally recycle the clippings, and save you time, money, and energy.

Also, there is about one-fourth pound of nitrogen in each bag of yard clippings. This free nitrogen acts a natural fertilizer and helps keep your landscape plants attractive and healthy. You can create useful compost with the clippings as well.

If you make a habit of leaving your grass clippings where they fall, then you’ll be rewarded with a green, healthy lawn.

Adapted from:

J. Bradshaw and L. Tozer, "Enviroscaping" (EES101), UF/IFAS Environmental Horticulture Department (Accessed 06/2014).

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