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

Friday - October 02, 2009

From: Georgetown, TX
Region: Southwest
Topic: Pests, Shrubs
Title: Purple sage with black residue on leaves in Georgetown TX
Answered by: Barbara Medford

QUESTION:

I have 2 very healthy tx. purple sage that have developed a black residue on some leaves, and is a "sticky" substance..any ideas what this is and how to treat???

ANSWER:

The Curse of the Common Name has struck again. You see, there are two very dissimilar plants that carry the common name "purple sage." One is Leucophyllum frutescens (Texas barometer bush), which we call cenizo and which is native to Central Texas. Four others are members of the genus salvia, a herbaceous blooming plant: Salvia dorrii (purple sage), Salvia dorrii ssp. dorrii (purple sage), Salvia dorrii ssp. dorrii var. incana (purple sage) and Salvia leucophylla (San Luis purple sage). While none of them are native to Texas, they could probably have been purchased from area nurseries.

In this case, which plant it is doesn't really matter because we think you have aphids, which are usually small and difficult to see, and the black stuff is a sooty mold which has grown on the sticky exudate of the aphids, called honeydew. This University of California Integrated Pest Management article on Aphids gives you information on control.  Neither the aphids nor the sooty mold are likely to cause real damage to the plant but are unsightly. When you read the article you will learn that a good stream of water on the plant will wash many of the offending little bugs off, and they can't get back up there after they are washed off. 

From our Native Plant Image Gallery:


Leucophyllum frutescens

Salvia dorrii

Salvia dorrii ssp. dorrii

Salvia dorrii ssp. dorrii var. incana

Salvia leucophylla

 

 

 

More Pests Questions

Tulip tree with white spots on leaves in Mississippi
July 31, 2008 - I have a tulip tree in my yard that blooms in the spring that is about 10-15 years old. However just this past week or so we have noticed that there is lots of white spots on the leaves and the branc...
view the full question and answer

Plants to repel mosquitoes from Leander TX
May 19, 2013 - What are the best plant for repelling mosquitoes in the Leander area? The land here is hilly and rocky.
view the full question and answer

Problems with Live Oak in Boerne TX
April 24, 2011 - I had my large Live Oak trimmed last year. This spring there seems to be a problem with leaf growth. Most leaves are small in nature and appear to have been attacked possibly by bugs. Many of the bran...
view the full question and answer

Landscaping for slope in Kansas City
October 08, 2008 - We have a down sloping back yard and patio on the lower area. We need some water absorbing plants near the foundation and some in the front of the house, where water isn't a problem. We are allergic ...
view the full question and answer

Need bug repelling plants in Arlington, VA
February 08, 2010 - What kind of plants are best bug repellents, and need little or no maintenance. I'm a city girl and don't like bugs (spiders)
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