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?


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

Sunday - August 22, 2010

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders
Title: Aphid infestation from hackberries in Austin
Answered by: Barbara Medford


I've got 5 hackberry trees in my yard and they are all heavily infested with woolly aphids! I wouldn't usually mind, but the aphids are now all over my newly planted native plants. I've read up on treating the plants, but I figure it won't be of permanent use because the main source is untreated. What's the best way to treat my hackberries? They are pretty tall and personally spraying them w/a high-pressure hose is out of the question. Help!!!


We are assuming you had the Celtis occidentalis (common hackberry) on your property when you moved  in because most people seem to look down their noses at these trees native to this area, drought resistant and sturdy.  Not only that, but hackberries are among the best food and shelter plants for wildlife; the fruit is relished by birds. From Bug Guide, we found these pictures of Woolly Aphids, not a pretty picture.

You are correct that spraying your tall trees would be a challenge, and the creatures will overwinter in the cracks of the bark on those trees. This University of California Integrated Pest Management website on Hackberry Woolly Aphids mentions several lines of treatment,  but, frankly, we don't think this is something an individual can handle. This article refers to another species of the genus Celtis, Celtis sinensis, Chinese hackberry, but we believe their suggestions for control would still be valid for the common hackberry. 

We hate to tell you this, but we think you may need professional help with the aphids in the trees. You can continue to treat your newly planted native plants, just to help them survive the onslaught. Soon, believe it or not, the leaves will be gone from the hackberries, and the spread of the aphids will stop, for the moment.  As the material we have referred you to says, the eggs of the aphids overwinter in the cracks of bark on the trees, and dormant treatments don't seem to be too effective. None the less, you are going to have to deal with the source, because they will be right back in the Spring. 



More Diseases and Disorders Questions

Problems with mature cottonwood in Justin TX
September 17, 2012 - I have a very large, 90" circumference, approx 60' tall, cottonwood tree in my front yard that appears to be sick. The trunk splits at about the 4' level into 2 parts. at that split is a 10" wide...
view the full question and answer

Distressed Red Oak tree in Pflugerville, TX.
July 22, 2012 - I have a large (40 ft) Red Oak tree in my yard that is distressed. It started with yellowing leaves, with darker veins. Then small brown spots appeared, followed by browning arount the leaves edges. N...
view the full question and answer

Death of lantana in Bryan TX
March 28, 2013 - I would like to know what killed several new gold lantana in a single bed that died over the winter. They looked quite healthy last fall. I have several other new gold lantana that survived the wint...
view the full question and answer

Willow woes in Philadelphia, NY
August 22, 2010 - I have a 2 yr old willow; it is August and it looks like the tree has gone dormant, is this normal?
view the full question and answer

Time for trimming oaks from Boerne TX
July 03, 2012 - I want to trim a native red oak but am scared to touch it because I dont want to lose it. It is the primary source of shade in our back yard. Also I want to trim the live oaks and am surrounded with O...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center