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

Thursday - June 13, 2013

From: Austin, TX
Region: Southwest
Topic: Non-Natives, Diseases and Disorders, Grasses or Grass-like, Trees
Title: Brown rings on grass under live oaks in Austin
Answered by: Barbara Medford

QUESTION:

There are brown rings in the grass at the dripline on several Live Oak trees in our neighborhood. What causes this? The trees appear healthy.

ANSWER:

You did not say what grass you or your  neighbors have. The rings might be a problem in the grass rather than originating from the tree. We will investigate brown rings in non-native grasses bermudagrass, St. Augustine and zoysia.

Although no grasses do well under trees, oak trees have more of an influence on the grasses. Oak, walnut, pecan and other trees exhibit allelopathy which means they exude substances harmful to competitive plants beneath them. Here is a a previous Mr. Smarty Plants answer on how we feel about lawns under trees. Between the shade, the allelopathy and the competition of extensive root systems for water and nutrients, grass growing under trees is always difficult. Since all three of the grasses we mentioned above are non-native to North America we don't know much about them, but will try to find some research to help you make a diagnosis.

Bermuda Grass: From WalterReeves.com Bermudagrass diseases - brown patch.

Zoysiagrass: From Missouri University - Issues of Zoysiagrass Lawns

St. Augustine Grass: From Cypress Isle (FL) Master Gardeners- St. Augustine Grass, Common Summer Problems.

Of course, if you are growing Bouteloua dactyloides (Buffalograss) or Habiturf they both need at least 5 hours a days of sun and won't be growing under the trees anyway.

 

More Non-Natives Questions

Removing a non-native windmill palm from Austin
February 27, 2013 - I have a fairly good size windmill palm (about 15ft high) that is planted too close to the house. I also don't like having to constantly remove its fronds as they block a walkway. Is there a good wa...
view the full question and answer

Plants for oak shade from Whitney TX
December 24, 2012 - I live in Whitney, Texas and have a number of beautiful Live Oak trees in a portion of my yard providing deep shade. Asian Jasmine grows in about 5 ft circle around them and then nothing! I have walk ...
view the full question and answer

Native or non-native hibiscus for Kansas
August 13, 2005 - I recently purchased a 10" Hibiscus flowering plant and would like to know how to care for it. How much water and sunlight does it need and how long I can expect it to live? It is a beautiful plant a...
view the full question and answer

Growing non-native grapefruit from seeds from Austin
April 30, 2013 - Can you grow ruby red grapefruit trees from seeds?
view the full question and answer

Elaeagnus sudden death in Waxahachie, TX
May 11, 2015 - I live in North Central Texas and have eleagnus planted along my fence in full sun. Last year one dropped all it's leafs and died. The same is happening to one beside it this year. I have sprayed ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center