Q: My backyard gets sun from noon until 7 p.m. in summertime. I would like to plant a tree that would give me some shade, but since it is going to be close to the house, I need a tree which the roots go straight down instead of harming the house. Any suggestions?
Nancy Rock, Davis
You need to consider the branches overhanging your roof as well as the roots near the foundation. But there are many, many possibilities to fit your requirements, from crape myrtles and redbuds to maples and oaks. First, consider the other growing conditions.
Whether or not a tree thrives in a given location will depend on several factors, says UC master gardener Annie Kempees. The No. 1 factor: Depth and type of soil on the property.
Some examples are:
▪ Soil with hardpan close to the surface;
▪ Clay soil that holds water and nutrients but does not drain well;
▪ Sandy soils that holds neither water nor nutrients; and
▪ Soil that’s rich and loamy with a mixture of clay, loam and sand, which holds water and nutrients more loosely than clay and usually has very good drainage.
No. 2: How will the tree be irrigated? Nearly all landscape trees thrive if grown away from lawns and have their own watering system that expands with the tree’s growth as its drip line – the furthest reach of its branches – widens. Trees grown and watered with a lawn usually develop shallow roots.
Where you plant a shade tree depends on the height and width of the tree at maturity. Based on recommendations from the Sacramento Tree Foundation, small trees that grow up to 25 feet need to be a minimum of 8 feet from the foundation and house overhang. Medium trees that grow 26 to 45 feet tall need a minimum of 12 to 17 feet from the house foundation and overhang. Big trees, those that grow more than 45 feet tall at maturity, require that 17-foot (or more) buffer zone, too.
The Sacramento Tree Foundation website, www.sactree.com, has information on many tree varieties for our area in addition to siting guidelines and general characteristics. The website also has extensive information on proper planting, staking and irrigation of trees.
Tree Davis has a list of recommended trees for your area; find it at www.treedavis.org. Davis soil contains the micro-nutrient boron. There are some trees that will not grow as well under this condition.
You also may wish to contact the Yolo County UC Cooperative Extension Office of the Master Gardeners at (530) 666-8143 for a list of trees that would perform best in your area.
In addition, you can find shade tree suggestions via Sacramento Municipal Utility District’s shade tree program. SMUD residential customers are eligible for free shade trees, but anyone can look at the list of recommended trees. Find it at www.smud.org and follow the links to “shade trees.”
Questions are answered by master gardeners at the UC Cooperative Extension services in Sacramento and Placer counties. Send questions to Garden Detective, P.O. Box 15779, Sacramento, CA 95852. Send email to email@example.com. Please put “Garden Detective” in the subject field and include your postal address. To contact UC Extension directly, call:
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Butte: (530) 538-7201;
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El Dorado: (530) 621-5512;
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Placer: (530) 889-7388;
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Shasta, Tehama, Trinity: (530) 225-4605
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Yolo: (530) 666-8737;
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