Host an Event Volunteer Join Tickets

Support the plant database you love!

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
1 rating

Tuesday - November 29, 2011

From: Dripping Springs, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Large oak with possible Laetiporus fungus
Answered by: Nan Hampton

QUESTION:

We have a huge oak tree in front of our new house. After the first rain this fall a large fungal growth appeared in an old knothole of the tree and I would guess that it is Laetiporus. A neighborhood street was cut just outside of the tree drip line in the last 7-10 years. Construction traffic also recently occurred on the lot, but again outside of the tree's drip line as we fenced off this tree and were very careful of it. Other than that, the tree appears to be very healthy. We watered it some toward the end of this summer, but even without that it looked the healthiest of all the trees throughout this drought. Should we treat the tree in some way to kill this fungus?

ANSWER:

The University of California Davis Integrated Pest Management (IPM) has an article, Wood Decay Fungi in Landscape Trees, that describes (with photos of the fruiting bodies) several types of fungi that grow in and on trees.  If your tree really does have the Laetiporus sp., the conks (fruiting bodies) showing on the outside of the tree indicate that there is probably extensive internal damage and that the fungus mycelia have been growing inside for many years.  As Michael Kuo says about Laetiporus sulphureus (The Chicken of the Woods):

"The mushrooms do not appear until well after the fungus has attacked the tree; by the time the chickens appear, they are definitely coming home to roost, as far as the tree's health is concerned."

And, from Disease Recommendations for Trees and Shrubs from the University of Michigan Extension Service:

"Fungus invades the roots, trunk and butt of tree through wounds causing a brown cubical rot. First evidence may be the production of a fleshy, yellow shelf fungus on the trunk. However, presence of the fungus suggests considerable rot within and possibility of a hazard tree should be investigated."

It seems that your best bet would be to contact a professional arborist to assess the extent of the internal damage and what the risk is that your tree could fall.   An arborist could also tell you whether there is an effective treatment to save the tree.  To find a professional arborist, you can search on the Tree Care Industry Association (TCIA) site; International Society of Arboriculture (ISA) site and/or the American Society of Consulting Arborists (ASCA).

 

 

More Diseases and Disorders Questions

Need help with dying clumps of Cedar Sedge
June 24, 2015 - Carex planostachys. This grass was planted 2 years ago in light shade. It grew well until this year. Now some clumps are dying. Others in same area look fine. No insects can be detected. Why are...
view the full question and answer

What kind of beetles are attacking cedar trees on Cape Cod, MA.
May 17, 2010 - I live on Cape Cod, MA and my cedar trees are being attacked by some kind of beetle & killing them. I would appreciate knowing what this could be and how to treat this. Thank you
view the full question and answer

Can a Quaking aspen grow in central Texas?
August 11, 2015 - I live in Austin and like the idea of a Quaking Aspen tree. I live on a creek and the tree(s) would get good sun and water. Am I crazy?
view the full question and answer

Habiturf installation after Take-All fungus
January 24, 2012 - Are other soil remedies needed (besides those listed in your Habiturf brochure) to install Habiturf on land which had a St. Augustine lawn which was decimated by take all patch.
view the full question and answer

Verticillium wilt in catalpa and maple
July 17, 2008 - On Monday - July 07, 2008, you answered a question about a catalpa and maple with the same problem--an entire branch died, and then more of the tree died. And both trees came from the same nursery. Th...
view the full question and answer

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