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?


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

Saturday - May 30, 2009

From: Buda, TX
Region: Southwest
Topic: Compost and Mulch, Diseases and Disorders, Shrubs
Title: Problems with Green Cloud purple sage in Buda TX
Answered by: Barbara Medford


I planted the "Green Cloud" variety of purple sage about 3 years ago. Yesterday, I noticed yellowish dots on the underside of the leaves of some plants. Is this harmful? The plants seem to be ok at this time, but I'd like to prevent any problems that might be brewing. I thought about the cotton root rot, but we have been in a drought.....not much water here (however,the area is heavily mulched).


There are 5 plants in our Native Plant Database with the common name "purple sage;" however, only one of them, Leucophyllum frutescens (Texas barometer bush), is native to Texas, so we will assume that it the one you are asking about. The species of this plant usually has silvery green foliage; "Green Cloud" is a selection which has green leaves and pinkish flowers. Pictures of Green Cloud.

We investigated the possibility of cotton root rot, but understand that this plant is pretty resistant to it. Another thing causing yellowing on leaves is chlorosis, the lack of cholorophyll, which is usually the result of the plant roots being unable to access trace elements, especially iron, in the soil. The key to both these problems is the drainage for the plant. Cotton root rot, for instance, is prevalent in calcareous clay loam, where drainage is poor. Chlorosis can be precipitated by too little drainage as well. So, the first thing you want to do is check that water is not standing on the roots of your purple sage. If water in a shallow depression stands there for more than about 30 minutes, your drainage is poor. You need some compost in the dirt in which the sage is planted, or it should be in a raised bed. Pull some of that mulch back, and work some decomposed matter into the soil as much as possible without damaging the roots. Let the lower branches get some air. Try gradually getting the air circulation improved and getting organic material into the soil, and see if that helps.

Leucophyllum frutescens

Leucophyllum frutescens




More Compost and Mulch Questions

Chlorosis in tropical milkweed and asclepias tuberosa
May 18, 2008 - I planted both tropical milkweed and asclepias tuberosa. Both are chlorotic and the native milkweed has brown upturned leaves. Could it possibly be too much water? Or what?
view the full question and answer

Privacy plantings in Texas
August 16, 2008 - Our home currently has a 4' chain fence. We are a family of 7 with younger aged children and are looking for more privacy. In lieu of a replacement fence, what would you recommend planting to provi...
view the full question and answer

Low maintenance replacement garden in Ashburn , VA
April 30, 2009 - We live in Ashburn, VA (Northern VA). Our house is 10 years old and the contractor grade plants have died. We are planning on digging everything up and re-doing the landscaping in our front yard - r...
view the full question and answer

Problems with Eves necklacepods (Styphnolobium affine)
March 25, 2008 - Mr. S-P, I urgently need your advice regarding two Eve's necklacepods that appear to be dying. They are in two completely different areas of my yard. One began leafing out and then the leaves sh...
view the full question and answer

Possible damage by invasive, non-native earthworms in compost
January 03, 2007 - I received a worm bin (vermicomposter) for Christmas. The instructions that came with the bin say to use the red wiggler worm (Eisenia foetida) and that it is okay if some of the worms go into your g...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center