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

Not Yet Rated

Monday - July 05, 2010

From: Lubbock, TX
Region: Southwest
Topic: Non-Natives
Title: Does non-native mimosa tree have a tap root from Lubbock TX?
Answered by: Barbara Medford

QUESTION:

Does a mimosa tree have a tap root? I would like to plant one next to a concrete driveway to help shade the garage and do not want to cause damage to the driveway in the future. Thank you in advance for your expertise.

ANSWER:

The Lady Bird Johnson Wildflower Center is dedicated to the growth, protection and propagation of plants native not only to North America but to the areas in which those plants are being grown. Albizia julibrissin, Mimosa or Silk Tree, is native to China and therefore out of our range of expertise. Read this article from the Plant Conservation Alliance's Alien Plant Working Group LEAST WANTED on the Mimosa or Silk Tree to learn why we do not recommend it, regardless of what kind of root it has.

You might also be interested in reading this Dave's Garden Forum page on Albizia julibrissin, especially the MANY negative comments.

There are few trees with a true taproot; they may begin with one, but as time goes by roots will spread from that center root, both in search of water and nutrients and also as a base to stabilize the tree in the ground. From this USDA Forest Service site Mimosa, we extracted these two sentences apropos of your question:

"Breakage: susceptible to breakage either at the crotch due to poor collar formation, or the wood itself is weak and tends to break."

"Roots: surface roots can lift sidewalks or interfere with mowing."

Honestly, most trees will interfere with foundations, sidewalks or driveways if planted too close, regardless of the type of root. Do your research on trees native to your area by going to our Recommended Species, clicking on Texas High Plains on the map, and Narrow Your Search to trees, and indicate the amount of light needed, moisture, etc. You can follow the plant links to the page on each tree to learn the projected size of that tree. Generally speaking, a tree root system can be from 2 to 4 times the size of the crown of the tree, so consider that when you decide where to plant a tree.