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 is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Friday - September 03, 2010
From: Austin, TX
Region: Southwest
Topic: Trees
Title: Pecan Trees in Austin, TX prematurely losing their leaves.
Answered by: Marilyn Kircus
QUESTION:
Why are the leaves on the pecan trees falling so early this year.ANSWER:
I suspect that you are seeing cultivars of pecans which may be much less resistant to stress and diseases, although “native” trees are possibly also being stressed to the point of losing their leaves. “Native” pecans are recommended for yard trees because of their greater natural resistance to stress and disease and because they don’t kill themselves by producing more nuts than they can actually support. “Native” in this context refers to trees that occur naturally and are not cultivated varieties.
Second, I’ve seen lots of pecan trees that lose leaves and also limbs when they don’t get enough water. The leaf fall is most likely a result of the current drought following on the heels of ample spring rains. I’m seeing lots of area trees shedding leaves as the drought goes on here. The excellent winter and spring rains we had encouraged lots of lush foliage on our trees. As a natural defense in the face of diminishing water availability, local trees are doing what plants do in this situation, they’re defoliating to reduce transpiration and protect the organism.
Third, through researching the problem of early leaf abscission – what you’ll find in scientific writings describing leaf drop – there are several other possible causes:
- Nitrogen deficiency causes leaves to yellow and in serious cases to fall off.
- Downy spot can cause early leaf loss in susceptible cultivar like 'Stuart', 'Pawnee' and 'Moneymaker'. It’s possible our wet spring gave this fungus a foothold.
- The Twig Girdler insect can cause small twigs to drop in late summer. Check to see if the leaves are attached to a small portion of the twig. There will be a perfect circle cut in the bark if this is the culprit.
This question falls under the bailiwick of State Agriculture Extension Services and I found several useful on-line publications. Check out the following links:
- From Texas A & M – Evaluating Pecan Problems2.
- From the University of Florida - The Pecan Tree
- From the Dirt Doctor who researches organic growing methods here in Texas – Pecan Tree
So, although I can’t give you a definitive answer, hopefully this information will assist you in determining why pecan trees in Austin are shedding their leaves prematurely.
More Trees Questions
Are Black Olive trees safe to have in pastures in Florida
May 06, 2009 - I am trying to find out if Black Olive trees will be safe to have in our yard and/or pastures. We raise cattle, goats and horses. We need to find some good shade trees that are safe for our animals ...
view the full question and answer
Identification of native dogwoods in Williamson Co., TX
March 12, 2007 - Hi Mr/Mrs SmartyPlants
What are the small-ish wild trees that are blooming so beautifully now? They are practically covered in pretty white blossoms. I've always called them dogwoods but in the vari...
view the full question and answer
Young oak damaged by falling tree from San Diego TX
June 27, 2012 - My neighbor's Palo Blanco tree was struck by lightning and fell over our fence and on to a young oak tree in our yard. We waited a few days to see if the neighbor would offer help, but he never did,...
view the full question and answer
Denying cows access to flowers through fence
March 20, 2008 - What flowers can I plant that cows will not eat? They stick their heads through the fence and eat anything they can reach. I would like to plant something in the fence row that will not hurt the cows...
view the full question and answer
Selection of native trees to replace trees lost in hurricane
September 28, 2008 - Hello, I have a tree replacement list I must choose from as I live in a HOA deeded area. I lost 2 pines to the hurricane. And according to them I need to replace with 2 large trees. The pines were 15 ...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |