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

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
Yellowing leaves on yaupon in Ft. Worth
April 23, 2009 - I planted a Pride of Houston Yaupon Holly in January in full sun. It is blooming little white flowers right now for spring, but a lot of leaves are turning yellow. Do you know what is causing this? ...
view the full question and answer
Leaf drop from maple tree in Minnesota
August 15, 2008 - I have about a 30 ft maple tree in my yard, last fall I trimmed it pretty good because the branches were getting low where you could not walk under it or get grass to grow. This is the 2nd time in abo...
view the full question and answer
Time to trim oak trees in Austin
October 29, 2011 - We have several large oak trees in desperate need of a good trimming. Given that the trees have had a very stressful drought year, when would be the best time to trim them?
view the full question and answer
Unknown ailment of Turk's cap in northeast Texas
July 01, 2013 - I just moved from the Dallas area to Emory in the north east part. I brought two young Turk's cap plants in pots. I had to leave the mother plant behind. The tops have a very curled and shrunken a...
view the full question and answer
White fuzz on Christmas tree from Lewisburg PA
January 04, 2011 - Our Canaan fir Christmas tree is now coated with white fuzz after being up for 4 weeks. The fuzz looks like spider webs, but it is also in clumps around the needles. When you rub your finger on it, ...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |