Native Plants
![](../_images/smarty_plants.gif)
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
![](../_images/mr_smarty_plants_logo_web_200w.jpg)
rate this answer
![](../_images/star_00.gif)
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
QUESTION:
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.ANSWER:
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
Leaves on new water oak turning brown from Matagorda TX
May 30, 2013 - We had water oaks planted in January when they had no leaves. Leaves came on but are now turning brown.
view the full question and answer
Freeze damage to Mexican olive in Austin
December 13, 2009 - I have a Mexican Olive tree/bush. It is young - about 8 ft. tall. This last freeze in Austin made many of its leaves turn black. I got this from your database: "Its native range extends no farther...
view the full question and answer
Salvia farinacea and rust fungus from Kerrville TX
February 22, 2014 - Are Henry Duelberg salvias (Salvia farinacea)susceptible to rust fungus?
view the full question and answer
Cedar trees dying in CO
July 18, 2011 - We have mature cedar trees at the home we bought in SW Colorado. The large ones have begun to die. Can too much water kill a cedar tree and is there anything I can do to keep them alive?
view the full question and answer
Live oak with brown balls and brown spots in Round Rock PA
August 01, 2010 - Is my live oak sick? Brown spots are on the leaves and round brown balls are growing on the stems. Please help.
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |