Rent Shop Volunteer Join

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

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

Wednesday - May 30, 2012

From: Austin, TX
Region: Southwest
Topic: Planting, Trees
Title: How close can house be built to live oak from Austin
Answered by: Barbara Medford

QUESTION:

We have a healthy 21" live oak tree on our lot and are planning to build a home in Circle C subdivision in southwest austin. The home foundation will be within 15' of the large live oak. Need your help assessing the following: 1. Is there a risk of moving/expanding root system causing foundation cracking in future ? What is a safe distance away from the live oak tree to build a home ? 2. Are tannins and other chemicals given out by live oak trees a problem to growing a lawn or other plants under the tree's canopy ?

ANSWER:

This is a question we get over and over, so we are going to refer you to some previous Mr. Smarty Plants Questions for some of the other answers.

No. 7884

No. 7413

No. 7427

No. 6917

No. 6844

No. 4701

Okay, we are sure you get our drift, and please don't shoot the messenger. You will have to make some hard decisions about where on your lot your house can be located, or if the tree is in danger of having to be removed to protect the house. We have given you a lot of information, but we can't make the decision for you.

In reference to Question No. 3, here is an extract from another former Mr. Smarty Plants question:

"Various studies have demonstrated that oaks can have allelopathic affects on surrounding plants. Allelopathy is the production of plant inhibiting chemicals by one plant to regulate the growth of others in its vicinity. One important group of chemicals produced by oaks is tannins. They are produced in leaves and litter and also directly by root systems in soil. Tannins are inhibitory to many organisms. Salicylic acid and other organic acids are also produced by oaks and are toxic to other plants. Allelopathy is species specific for the oak in question and the species that is inhibited."

In other words, it depends on which plant and which oak, and we don't have lists of plants that will grow under specific species of oak."

And then, of course, there is the shade cast by a healthy live oak, which also affects negatively the growth of plants beneath it.

 

From the Image Gallery


Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

More Planting Questions

Fastest growing shade tree for Austin.
April 27, 2015 - What is the fastest growing shade tree suitable for Austin? We are anticipating selling or renting our house in two to three years and want a shade tree for a baked full sun area of the yard that will...
view the full question and answer

Transplanting a redbud in August from St. Louis MO
August 09, 2011 - I have a 4' tall redbud that needs to be transplanted before the end of August because of construction on our house. Can this be done without killing the tree? Can I take a cutting from the tree and ...
view the full question and answer

Kinnikinnick for a green roof
July 04, 2012 - Hi Mr. Smarty Plants, I live just north of Seattle and want to build a green roof (outdoor kitchen) I'm concerned about the weight of the soil (saturated), drainage etc. am building from scratch and...
view the full question and answer

Shrub that will grow outside in Zone 5 from Millbrook NY
April 21, 2012 - Is there any shrub, tree or other sort of plant that will grow well in zone 5 in a very large container outdoors?
view the full question and answer

Submerged paving under lawn
September 07, 2008 - I had 4 patches of rectangular areas (about 4'x6'or more) in my lawn where the grass is fine in spring but totally dies in summer. I decided to till these bare patches so that grass may grow better...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.