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?


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

Wednesday - November 09, 2005

From: Lexington, TX
Region: Southwest
Topic: Diseases and Disorders
Title: Cotton root rot in Purple Sage, Leucophyllus frutescens
Answered by: Joe Marcus


We had three Purple Sage shrubs in our front yard. They did very well for about three years and then this past year they just died. From what I have read they are pretty hardy so we are really stumped as to what happened to them.



Purple Sage, Leucophyllum frutescens is also known as Cenizo, Texas Ranger, Texas Sage, Barometer Bush and Silverleaf. It is a tough-as-nails shrub native to south Texas.


Purple Sage is highly resistant to most insect pests and diseases. However, it is susceptible to Cotton Root Rot (Phymatotrichopsis omnivora) in poorly drained soil, in over-watered landscapes or during wet seasons. Once Cotton Root Rot, also known as Texas Root Rot, has infected one plant in a landscape, the pathogen stays in the soil and will infect other susceptible plants that replace it. The much-used Red Tip Photinia, Photinia xfraseri is particularly susceptible to Cotton Root Rot and is responsible for many of the occurrences of the disease that we see.


To positively identify Cotton Root Rot, it is best to pull a dead plant out of the ground, shake off as much soil as possible away from your landscape, and take the plant -- roots and all -- to your county agriculture extension office. For more information on this particularly pernicious fungal disease, see this article on Diseases of Urban Landscapes.


More Diseases and Disorders Questions

Freeze-damaged Texas Mountain Laurel in Austin, TX.
May 05, 2011 - I have a Texas Mountain Laurel (Sophora secundiflora) that is several years old. During this past winter, one of the freezes we had split one of the largest trunk right below the soil line. T...
view the full question and answer

Stressed live oaks from Lakeway TX
August 19, 2013 - I have some Live Oaks who appear to be stressed (Ball Moss is becoming very prevalent on some of them) during the drought in Central TX. How often and how long should I water them? Thank you very much...
view the full question and answer

Yaupon in bonsai failing to thrive in Lufkin TX
July 16, 2009 - Hi,I have a yaupon that I've turned into a bonsai. It's been producing new vegetation until about a month ago. Then all of a sudden the branches started drooping and the leaf tips started turning bl...
view the full question and answer

Diseased cypress trees in Connecticut
June 09, 2009 - Cypress trees in Connecticut browning on interior. Tips of longer limbs completely brown, single limbs dying one at a time, sap oozing out of mainstem underneath dying limb. I do not see any canker...
view the full question and answer

Brown patches on St. Augustine grass
April 24, 2009 - I have brown patches on my st. augustine grass, it looks like the grass has rotted from standing water, but the drainage is not a problem, What could it be?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center