En EspaŅol

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?

Share

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Sunday - August 02, 2009

From: Katy, TX
Region: Southwest
Topic: Shade Tolerant
Title: Shade trees not invasive to foundations and driveways
Answered by: Nan Hampton

QUESTION:

I am in zone 9. What shade trees can I plant that will not be invasive to foundations or driveways? Thank you, Mr. Smarty Plants

ANSWER:

The general thought is that trees with tap roots will prevent damage to nearby driveways, sidewalks and foundations.  Certainly, avoiding trees with extensive lateral roots will help prevent damage.  Mr. Smarty Plants answered a similar question a few days ago so part of the following is excerpted from the answer to that question:

"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.

You could consider installing some sort of root barrier between the tree and the wall.  Here is more information about root barriers."

Here are some large shade trees that are considered tap root trees that are recommended for Harris County:

Quercus macrocarpa (bur oak) and more information

Juglans nigra (black walnut) and more information

Carya illinoinensis (pecan) and more information

Ostrya virginiana (hophornbeam) and more information

Quercus virginiana (live oak) and more information

Quercus alba (white oak) and more information

You can use the Texas Forest Service Texas Tree Planting Guide to select other trees according to your own criteria.


Quercus macrocarpa

Juglans nigra

Carya illinoinensis

Ostrya virginiana

Quercus virginiana

Quercus alba

 

 

More Shade Tolerant Questions

Groundcover to help ease erosion in shade
May 17, 2008 - My house is situated on an embankment near a creek. We are looking for ground cover plants that can help ease the erosion of the embankment without being invasive for the existing trees. They must be...
view the full question and answer

Plants for northern exposure in Wichita, KS
March 17, 2009 - What are good plants for the north side of the house with acidic soil in Zone 6, Wichita, KS?
view the full question and answer

Oak leaf hydrangeas from Edwardsville IL
August 13, 2012 - Hello, I live in West Central Illinois (across the river from St. Louis) and I am considering planting several Oak leaf Hydrangea's in my yard. The location where I would like to plant them is und...
view the full question and answer

Plants for under Oak Trees in LA.
March 05, 2013 - What type of plants and grass can be planted under and around oak trees
view the full question and answer

Native plants for shady small spaces in Houston, TX
June 18, 2006 - What are the best plants and flowers to plant in small spaces in an urban area in Houston, Texas? I have several flower beds that are 3 foot wide and 10-12 foot long that get half day sun. The area...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center