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

Proper deadheading of non-natives Arabian Jasmine and Crape myrtle from Las Vegas
July 23, 2010 - Advise please on proper deadheading of Arabian Jasmine, and of Crape Myrtle. They are both blooming great but I want to know once the petals fall should I deadhead and will it help them to bloom agai...
view the full question and answer

Failure to bloom of non-native lilac in Plymouth MD
July 18, 2009 - My five year old lilacs are not blooming, WHY?
view the full question and answer

Red pods on Canna Lilies from Windsor VA
July 21, 2013 - What are the dark red pods on my canna lilies?
view the full question and answer

Problems with non-native Chinese pistache tree in San Jose CA
May 30, 2009 - We have a Chinese Pistache tree that is between 25 and 30 years-old. Over the past couple years, we have observed more and more branches dying. They turn black, and remain leafless in the spring, when...
view the full question and answer

Mulching vegetables with straw
June 13, 2007 - I have a small garden with 4 different veggies, tomatoes, hot peppers, squash & cucumbers. which plants is it OK to put straw under? which plants will straw hurt the stalks or other possibilities? tha...
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