En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Purple sage with black residue on leaves in Georgetown TX

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

How to keep persimmons from staining patio
August 10, 2008 - We have approximately 4 female persimmons bearing fruit around our back patio. Birds are carrying the berries to our patio and eating them which leaves a dark stain on our patio. I'm having to go o...
view the full question and answer

Why are small leaf pieces aligned on top of exposed root?
July 11, 2011 - Hi. An oak tree in my yard has one of its exposed roots covered in hundreds of small pieces of leaves. The pieces follow exactly the shape of the root above the surface. What insect would do this and...
view the full question and answer

Non-native Chamaecyparis pisiflora turning brown in Fuqua-Varina NC
December 10, 2012 - I have a "Soft Serve False Cypress" Chamaecyparis pisifera'Dow Whiting PPAF, that has only been in the ground for 6-7 months. I just noticed that the branches and leaves are starting to die, turni...
view the full question and answer

Worms on blackeyed susans and daisies in Tuckerton NJ
July 30, 2009 - I have black eyed susans and white daisies planted together. Not sure if this makes a difference. Today I noticed that there are tiny worms on both the plants they are almost the size of silk worms. ...
view the full question and answer

Yellow jackets on non-native crape myrtles
September 25, 2008 - Hey Mr. Smarty Plants I have only 1 question. I have several Crape Myrtles that have numerous amounts (alarming) of yellow jacket bees on them. who what where when why etc? Should I be concerned? tha...
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