This intensely hot time of year, I like to remind people how important shade trees are in our landscapes. Now is an excellent time to evaluate your landscape and determine where additional shade is needed. Energy bills rise right along with the temperatures, but shade trees can help keep your home cooler and lower your electricity bills.

Trees that shade the house during the summer can lower air-conditioning bills by blocking the sun from the windows, exterior walls and roof. Air conditioners cooling a fully shaded house have been shown to work only half as much as those in a house that has its walls and roof exposed to the sun. Other research reports show that shade trees will reduce heat gains significantly depending upon their placement and density. A well-placed shade tree is a better energy saver than interior venetian blinds or curtains.

Deciduous trees that drop their leaves during the winter are generally the best choice. These trees provide shade during the summer when it is needed, and let the sun shine on the house in the winter when the sun’s added warmth is welcome. Evergreen trees, which retain their foliage in the winter, provide constant shade, which is generally not desirable when it is cold.

Some people consider evergreen trees neater because they do not drop leaves that have to be raked up. This is not necessarily the case. The evergreen Southern magnolia is one of the messiest trees we grow here. Evergreen trees would be desirable, however, where a windbreak, noise barrier or screening for privacy is needed.

The location of your shade trees is very important when it comes to how well they will help reduce energy consumption. Trees should be planted on the southwestern and western side of the house to be most effective. Trees in those locations will shade the house from the most intense sun during the hottest part of the day. Planting trees to the south and east will also help shade the house. Trees located to the north of the house are not as effective.

Planting trees for energy conservation doesn’t mean that you should completely surround your home in a forest of trees. People frequently plant too many trees on their property, not realizing how large they will become later on.

Trees also need to be planted the proper distance from the house and away from concrete areas such as sidewalks and driveways. Although house slabs are generally not affected by tree roots, thinner concrete surfaces, such as patios, driveways and sidewalks, can be damaged by roots from trees planted too close. The recommended distances are generally related to the mature size of the tree. Larger trees, such as oaks, should be planted at least 15 feet away from sidewalks, driveways and the house, while smaller trees, like yaupon hollies, should be planted about 8 feet or more from concrete surfaces.

In addition to shading the home, decide on other areas where shade is necessary or desirable. Outdoor living areas such as patios are unusable here in the summer without some sort of shade, which properly placed trees could provide. Choose small-growing trees for planting close to patios, as they are more in scale with the surroundings and are less likely to damage surfacing materials.

When landscaping for energy conservation, deciding on the right placement, number and type of trees requires careful planning, but you have plenty of time to think about it. Although now is the time to make decisions on where shade is needed and where to plant the trees, the ideal tree planting season here is November through February.

So, use the next couple of months to study your landscape carefully and decide where shade is needed. Then determine what size tree will do the job. Generally, medium-size trees, those that grow 30 to 55 feet tall, are suitable as primary shade trees in average size urban lots. These are large enough to shade your house. Avoid large trees with a height of 60 feet or more or a spread over 40 feet, such as sycamore, pecan and live oak, unless you have a property large enough to accommodate them. Small trees, which grow 15 to 25 feet tall, are suitable for planting closer to the house and are particularly useful for shading smaller situations, such as a patio or deck area.

In addition to size, think of any other important characteristics you might want the tree to have. I’ve already mentioned that deciding whether the tree should be evergreen or deciduous is important. Other characteristics you might want to consider are attractive flowers, rate of growth, interesting bark, the overall form of the tree (more upright or spreading), trees that produce berries or nuts that help feed wildlife, attractive fall color and so on.

Look through references, check with friends and neighbors about their trees, and talk to horticulturists at your local LSU AgCenter Extension office and nurseries. Selecting a tree is a very important decision, but with some careful thought and research, you will know just the right trees for your landscape when it comes time to plant them in November.

Gardening in the heat

Speaking of dealing with high temperatures, working outside in especially hot weather places extra stress on our bodies. As sweat draws moisture from the body, dehydration occurs. This can cause headaches, weakness, nausea and sometimes, if your body temperature rises, even lead to heat stroke. Gardeners working outside may lose up to 2 quarts of water each hour.

To prevent dehydration, drink before, during and after working outside. It is especially important for the body to have a good storehouse of fluids well before the start of outdoor activities. Drink before you’re thirsty.

Work in your garden in the early morning or late afternoon when it is cooler and stay in shady areas as much as possible (a well-placed beach umbrella can provide shade wherever needed). Wear a hat, loose, comfortable clothing and use sunscreen and mosquito repellent whenever you go out to work in the garden. Also, take frequent breaks and try not to stay outside in the heat for extended periods.

Dan Gill is a retired consumer horticulture specialist with the LSU AgCenter. He hosts the “Garden Show” on WWL-AM Saturdays at 9 a.m. Email gardening questions to gnogardening@agcenter.lsu.edu.