Rent Shop Volunteer Join

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

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

Monday - August 23, 2010

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders
Title: What's that sticky stuff on plants under many trees?
Answered by: Jimmy Mills

QUESTION:

Here in Austin, I've recently noticed a sticky film appearing on shrubs, flowers, grass, etc. under many trees. It appears to be coming from the trees under which they are planted. The sticky film seems to be attracting white flies and other pests to these plants. Is there currently some sort of tree insect infestation that is causing this or are the trees stressed due to the recent heat? It doesn't appear to be moisture due to transpiration.

ANSWER:

What you are experiencing is the annual onslaught of honeydew here in Austin. Honeydew is a waste-product of aphids and other sap-sucking insects such as scale. As honeydew is excreted by sucking insects, it falls and coats any surface upon which it lands. Here is a previous answer from last Fall.

This article from University of Minnesota Extension , and another from the University of Kentucky College of Agriculture  give a rather thorough explanation of honey dew and aphids and their effects on plants.

You may also notice blackening of the plants under the trees because of an infestation of sooty mold that grows on the honeydew.

 


 
 

More Diseases and Disorders Questions

Browned foliage on Juniperus ashei in Wimberley TX
April 03, 2011 - We are in Central Texas and have native "cedar" juniper trees. One with foliage that looked brown, on close inspection, is covered with white webs. The foliage looks like it is dying. No worms a...
view the full question and answer

Red spider mites in native bluebonnets in Austin
April 02, 2008 - What would you do if the WFC bluebonnets developed a bad case of red spider mites? That is what has happened to many of mine here in Austin. I noticed them the other day and I must have been asleep be...
view the full question and answer

Care for heritage roses
October 07, 2007 - Dear Mr. SmartyPlants, I took some cuttings from an antique rose my grandmother had.I had good luck , had some of them grow for me. Some of them have blooms and others are long and lanky stems but n...
view the full question and answer

Danger of oak wilt infestation in trees with storm-damaged limbs
June 15, 2007 - A recent severe storm in Southwest Austin broke large branches and trunks on many Live Oaks in my neighborhood, including my next door neighbors'. Can this invite Oak Wilt? I'm worried about my tree...
view the full question and answer

Esperanza with rust spots in Corpus Christi, TX
November 30, 2009 - I have a young esperanza plant and the leaves have what looks like rust spots all over them. What is the cause of this and what can I do for it? My other larger and older esperanza does not have this....
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.