En Español

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
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

Plant identification
June 11, 2010 - Dear Mr Smarty Pants.I hope you can help to save my sanity! I am a true believer in using native plantings, having a yard that is 99% native. I hope that fact provides me a little extra credit towar...
view the full question and answer

Landscaping large area in Webster KY
February 10, 2012 - We just bought a house that we fell in love with. The land around it . . . well it has GREAT potential but is seriously lacking at the moment. Trying to get the farm up and running leaves very litt...
view the full question and answer

Eliminating KR? Bluestem from St. Augustine Yard in Spicewood, TX
April 28, 2012 - How can I eradicate bluestem grass invading my St. Augustine lawn?
view the full question and answer

Covering dead arborvitae with non-native ivy from Niles MI
April 14, 2013 - I have a severely thinning arborvitae hedge. It is probably too shady, but I want the privacy. I'm thinking of planting something like ivy to fill the gaps. I know it will probably kill the hedge, bu...
view the full question and answer

Bark splitting on non-native Royal Poinciana in tree in Merritt Island FL
August 10, 2010 - Information on splitting bark along the branches like an overstuffed sausage: A royal Poinciana tree, about 5 years old. The upper branches are doing this, although I'm afraid little splits or tear...
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 | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center