Native Plants

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.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants

See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

rate this answer

1 rating

Monday - September 07, 2009

From: Coppell, TX
Region: Southwest
Topic: Trees
Title: Tree with tap root for small area near Dallas
Answered by: Nan Hampton

QUESTION:

Mr. Smarty Plants, I live in Coppell, TX (a suburb of Dallas) & am looking for a tree to plant near our pool to provide some shade. The current tree (a silver leaf maple) is dying. My husband thinks we need a tree w/ a tap root system. The size of the area for planting the tree is about 5 ft x 5 ft. What would you suggest? Thank you very much.

ANSWER:

Your husband is no doubt worrying about the roots of the tree causing damage to the pool and other nearby structures. Here is information from the answer to a question we received a few weeks ago about trees with tap roots:

"Although trees are generally divided into two groups by root type—tap root trees (such as oaks, hickory, walnut, conifers) and lateral, or fibrous, root trees (maples, ash, cottonwood)—this distinction is most evident as seedlings or saplings. Once the tree is planted and begins to mature, the distinctions between the root types become less pronounced. Then, the depth and lateralness of the roots is greatly dependent on the soil condition. Highly compacted soils, soils with low oxygen content and soils where the water table is near the surface are not likely to produce a strong tap root. Their roots are more likely to be lateral and located very near the surface with the majority of the roots located in the top 12 inches of soil. Also, it is important to realize that the spread of the roots can be at least 2 to 4 times greater than the drip line of the branches.

You can read the recommendations from Iowa State University Extension Service for Sidewalks and Trees which bases the distance trees should be planted near pavement on the mature height of the tree. Their recommendations are:

1. trees with a mature height of less than 30 feet, 3-4 feet from pavement,
2. trees with a mature height of 30 to 50 feet, 5-6 feet from pavement,
3. trees with a mature height of greater than 50 feet, at least 8 feet from pavement."

Because of the small size of your space, I will suggest several smaller trees. Here are some trees that have a maximum height of 30 feet or less:

Cotinus obovatus (American smoketree). Here is more information.

Frangula caroliniana [syn. = Rhamnus caroliniana] (Carolina buckthorn). Here is more information.

Cercis canadensis (eastern redbud) has a rapid growth rate of 15 to 30 feet. Here is more information.

Viburnum rufidulum (rusty blackhaw). Here is more information.

Ilex vomitoria (yaupon). Here is more information.

You might be able to get away with smaller medium-sized trees. All of these next ones would be considered medium-sized or small trees with a maximum height of less than 50 feet.

Fraxinus texensis (Texas ash) has a rapid growth rate and is long-lived, 30 to 45 feet. It also has beautiful fall foliage. Here is more information.

Acer grandidentatum (bigtooth maple) has both a tap root system and lateral roots, a moderate growth rate up to 50 feet and beautiful fall foliage. Here is more information.

Quercus laceyi [syn. = Q. glaucoides] (Lacey oak). Here is more information.