Native Plants
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.
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.
rate this answer
Monday - April 20, 2015
From: Austin, TX
Region: Southwest
Topic: Pests, Trees
Title: Black Sap from Live Oak in Austin, Texas
Answered by: Anne Van Nest
QUESTION:
We live in South Austin and our neighbor has several beautiful, enormous Live Oak trees whose canopies hang over into our yard. This past week, they've begun dripping some sort of black sap all over our backyard. Is this normal, or some indication of something wrong with the trees? Thank you!ANSWER:
Most likely your tree has an insect called an aphid feeding on the foliage. Aphids are soft bodied insects and when they are numerous you can see the released sticky "sap-like" substance called honeydew. When the honeydew is numerous and stays on objects or leaves for a lengthy period a black sooty mold begins to grow on the sugary substance. Also bees and wasps are attracted to the honeydew that is being released by the aphids. Have an arborist take a look at your tree to determine if any action is needed. Aphids are a fairly regular visitor to Austin gardens - some years worse than others.
From the University of California Integrated Pest Management Program, here is an article on managing aphid infestations.
Also here's a link to a previous Mr. Smarty Plants question about aphids.
From the Image Gallery
More Pests Questions
Larvae infesting Mexican white oak
December 16, 2010 - What larvae/worm would dwell and eat the inside of a Mexican White Oak? I planted one last November and it was doing great. The bark started cracking towards the bottom but the top was very full & gre...
view the full question and answer
Possible freeze damage in Wax Myrtle from last winter in Bastrop, TX
July 25, 2011 - Our Wax Myrtle is about 7 yrs old and in good shape until this past winter when we had several very hard freezes. Now several of the large branches are dead and more are dying each month. We have not ...
view the full question and answer
Problem with mesquite tree limbs
June 13, 2014 - i keep finding some smaller branches of my mesquite tree in the turf area around the tree. when looking at the cut ends, they appear to have a smooth cut around the circumference of the limb about 1/...
view the full question and answer
White specks on unknown houseplant from Ridgeway SC
June 20, 2013 - I have an unknown houseplant that seems to have some sort of pest or disease on it. It has white snowy specks atop its leaf. I bought this purple fuzzy leafed houseplant from Walmart in Winnsboro, SC ...
view the full question and answer
Falling Balls from an Oak in Kingsland TX
May 25, 2015 - I have a large Live Oak in the back yard, with St. Augustine grass under it. It is April 3, 2015. The leaves have fallen and now little tiny round balls are falling. I am hearing a popping noise und...
view the full question and answer
| Support the Wildflower Center by Donating Online or Becoming a Member today. |