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
6 ratings

Friday - July 31, 2009

From: Denison, TX
Region: Southwest
Topic: Shade Tolerant
Title: Shade trees with a tap root
Answered by: Nan Hampton

QUESTION:

I need a list of shade trees with a tap root system. I would also like the tree to grow at a medium to fast rate. I will be planting near a concrete wall and do not want the roots to do any damage to it.

ANSWER:

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.

All that said, here are some trees that are recognized as having tap roots.  All of these 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.

Juglans microcarpa (little walnut) has a moderate growth rate of 20 to 50 feet.  Here is  more information.

Quercus buckleyi (Buckley oak) has moderate growth of 15 to 50 feet and colorful fall foliage.  Here is more information.

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


Fraxinus texensis

Acer grandidentatum

Juglans microcarpa

Quercus buckleyi

Cercis canadensis

 

 

 

More Shade Tolerant Questions

Will Salvia coccinea bloom in shade in Houston?
June 02, 2010 - I live in Houston and I used your database tool to search for shade plants. I am particularly interested in plants that bloom and support native pollinators. My search returned salvia coccinea. Will t...
view the full question and answer

Ground cover under Juniper for San Antonio
September 14, 2012 - I have a shaded area under juniper in the Hill Country of Texas that has many sprouts from the tree. We have to weed whack it to keep them under control. What ground cover could I use to enhance tha...
view the full question and answer

Shade plants for a childrens garden in Magnolia, TX
June 21, 2009 - What shade plants would be good to plant in a Children's garden at a learning center?
view the full question and answer

Plants for the Shade of a Pine Tree in Pittsburg
June 03, 2013 - I live in Pittsburgh, PA. My neighbor has a huge pine tree. Last year everything I planted on that side near the tree died. That part of the yard only gets morning sun, as the tree overshadows it. Wha...
view the full question and answer

Silverleaf Nightshade, Happy in El Paso Texas
June 14, 2011 - Trying to identify a small wildflower all over in our El Paso neighborhood. Lavender bloom, five pointed petals, Star pattern inside, five bright yellow pistols. Beautiful. Thanks!
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