Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
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.
From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders
Title: What's that sticky stuff on plants under many trees?
Answered by: Jimmy Mills
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.
Possibility of oak wilt in red oak in Austin
December 25, 2010 - I planted a Red oak tree in Austin January 2008. It was container grown but decent size, over 15ft tall. This summer (2010) its leaves turned color as if it were fall and started dropping. I starte...
view the full question and answer
Fungus type problem on native blackeyed susans in Ohio
August 20, 2008 - I have black eyed susans that have recently developed a black fungus type problem in the bottom and on the leaves. The flowers are now wilting and dying. What is this and how can I stop it from possib...
view the full question and answer
Problems in non- native weeping willow in Spokane WA
June 21, 2010 - My wife and I have a weeping willow tree that has done well for two years. This year some of the branches are loosing their leaves in late spring in Spokane, WA. I though it was from the wind but ha...
view the full question and answer
Failing to thrive of non-native rose bushes in Austin
September 24, 2012 - I live in NW Austin and I have lost one knockout rose bush this summer and it looks like another one is failing. The leaves on a cane turn yellow then brown. I do not see whiteflies or black spots o...
view the full question and answer
What are the green round growths on the edges of my oak leaves in Fairfax, OK
May 21, 2013 - round growths on the edge of oak leaves. ranging in size from a pearl to a lime. ranging in color from pale green to lime green. hollow, small ones appear to contain one small gnat sized seed. the la...
view the full question and answer
![]() |
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. |