Native Plants
![](../_images/smarty_plants.gif)
Q. Who is Mr. Smarty Plants?
A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
![](../_images/mr_smarty_plants_logo_web_200w.jpg)
rate this answer
![](../_images/star_00.gif)
Wednesday - April 21, 2010
From: Austin, TX
Region: Southwest
Topic: Shade Tolerant
Title: Tree as shade alternative to carport in Austin
Answered by: Barbara Medford
QUESTION:
Hello, I'm looking for a small tree that could provide afternoon shade for two cars, as an alternative to a carport. When mature, the tree would need to be tall enough to grow around (and above) the nearby mature Texas Mountain Laurel, and it would ideally be free of low branches so as not to obstruct car access. The site is bounded by a driveway and a curb. Our topsoil is good, but there is some clay deeper down.ANSWER:
Our advice is, don't do it. To have hope of being successful planting a tree, it would have to be quite small and still could have transplant shock. The site you describe, bounded by a driveway and a curb, is also risky. Any tree's roots are going to extend as much as 3 times the drip or shade line of the tree. Either the driveway, curbing and the street beyond it is going to hurt the roots, or the roots are going to push up and crack the concrete. They just don't co-exist well. You might have to wait 10 years for a tree to get up tall enough to shade the 2 cars, by which time you could have well moved on to somewhere with a 2-car garage or even existing trees. But, to us, the most compelling argument against deliberately planting trees over a parking area is the mess. It doesn't much matter which tree it is, or what time of year, something is always dropping. Surely you have seen the cars with what looks like green fur on them driving around Austin? And where have they been? Why, parking under an oak which has been dropping its lovely allergenic green blossoms. And how about aphids getting in the trees? They you have that charming aphid by-product, honeydew, making a sticky mess on your car. If you plant a fast-growing tree that doesn't take the time to develop a very strong structure, a windstorm or snow (which we now know can happen in Austin) could drop a branch on the "protected" car. Leaves, seeds, acorns, bugs, twigs and branches-we love trees, too, but they make lousy carports.
Since you asked, we will suggest some locally native trees that would be nice. As for trees with no low branches, the only way you avoid low branches is to prune them up as the tree grows. And you can't trim them up until the upper parts of the tree have developed enough leaves to nourish the tree. We chose these four trees because they are native in and around Travis County, are considered good shade trees, and have moderate to fast growth rates.
Possible Shade Trees Native to the Austin Area:
Carya illinoinensis (pecan) - deciduous, takes 15 to 20 years before it starts bearing pecans, best production is on trees 75 to 225 years old. From Floridata: Carya illinoiensis
Fraxinus texensis (Texas ash) deciduous, 30 to 45 ft. tall, moderate to slow growing
Platanus occidentalis (American sycamore) - deciduous, 75 to 100 ft tall, fast growing, can reach 80 ft. in 20 years or less Floridata American Sycamore
Taxodium distichum (bald cypress) - deciduous, grows to 50 to 75 ft. or taller, moderately fast-growing, reaching 40 to 50 ft. in 15 to 25 years. USDA Forest Service Baldcypress
From our Native Plant Image Gallery:
More Shade Tolerant Questions
Variety of native tall plants for a screen in shady area near Ft. Worth
June 12, 2007 - Hello, we live west of Ft Worth. We are looking for tall plants to form a visual screen along a chain link fence we share with a neighbor. We have post oaks there and it is very shady and the ground ...
view the full question and answer
Container plants for Arlington TX
February 10, 2012 - Mr. Smarty Plants, I just moved to Arlington, TX. I am trying to create a container garden on my apartment balcony. What flowers, herbs, vegetables, and fruit combinations can I put together that wil...
view the full question and answer
Plants for a moist, wooded area in North Carolina
December 06, 2014 - I am looking to plant some native flowers in a wooded area in Surry County NC. The chosen location is fully shaded beside a creek. The water table typically sets about 2 feet below the surface of th...
view the full question and answer
Vine for complete shade in California
December 21, 2012 - I'm looking for a vine to put over my back door which is in complete shade.
view the full question and answer
Native Plants for Shaded North Slope in Ohio
January 03, 2013 - I have a shaded north hillside which needs erosion control plants. Mostly moss and very thin grass grows there now. Please help!
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |