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 Shrubs Questions

Problems with yellow lantana in Smoaks SC
June 05, 2010 - My yellow lantanas are about five years old - big and beautiful, but beginning last year, the blooms are small and part of the tiny petals are brown or black. Can you tell me what I can do about this ...
view the full question and answer

Dwarf, Evergreen Shrub Suggestions for Staten Island
August 14, 2013 - I had two rows of bushes in the front of my house. The back row of bushes is what is commonly known as a hedge. Unfortunately due to Sandy I lost the front row of bushes. Please help me, I am in conta...
view the full question and answer

Shrubs for New Hampshire
June 25, 2009 - Will be landscaping next Spring: Do you think using 'Ilex Crenata'-Japanese Holly together with variegated Euonymus (species: fortunei) as shrub hedges in front of our house is a good combo? Do they...
view the full question and answer

Shrubs for fenceline in Houston
September 13, 2009 - I live in Houston, TX and would like your suggestion on what plants, trees or shrubs would work best to grow alongside a fence to hide a neighbor's backyard. We all have relatively small backyards.
view the full question and answer

Privacy screen for Pace Florida
March 10, 2014 - We live in the Florida panhandle and I wondering what we could use as a natural fence line between our property and the neighbor's. I love the look of oleander, but upon research found it to be toxic...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center