En EspaŅol

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?


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
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.
rate this answer
1 rating

Tuesday - August 02, 2011

From: Del Rio, TX
Region: Southwest
Topic: Watering, Drought Tolerant, Trees
Title: Dormancy in Pin Oaks without water in Del Rio, TX
Answered by: Jimmy Mills


Can Pin Oak trees go dormant without enough water? If so how long can they live that way? Can they be brought back to producing leaves? If yes, then what do I need to do besides giving them water. I don't wont to cut them down if they have a chance of coming back. Thank you for your help! :)


The short answer is yes, but they can also die without enough water.

But first, lets learn more about Pin Oaks Quercus palustris (Pin oak) . Clicking on this link takes us to its NPIN page, where we find that it is  a handsome lawn tree with shallow fibrous roots and high water use. Next, scroll down the page to the Additional Resources Box and click on the plant name beside USDA. This brings up the USDA Plants Profile page with a Distribution Map that indicates that Pin Oaks do not occur naturally in Texas. So we seem to have a tree in the wrong place, and perhaps, running out of time.

Plant dormancy is a survival strategy (see link)  that allows plants to live through unfavorable conditions. We most often think of it in the Fall where a series of programed processes take place that get the plant  ready for the freezing weather of winter. The most obvious results are the change of color of the leaves before they fall from the tree. The changing of the length of days and nights seems to be the environmental cue that triggers these changes.

Drought can also trigger dormancy as a result of stress on the plant due to a lack of water. One of the important processes that is going on in the leaves of the plant is photosynthesis which absolutely requires water. When water is scarce, the plant attempts to conserve water, and this can happen in at least three ways: the leaves can wilt, they can turn brown, or they can fall off. All of these shut down photosynthesis which reduces the demand on the roots for water.

What is the situation with your Pin Oaks? Are the leaves brown, or have they fallen off?  Before you proceed, you need to determine if the trees are still alive by applying what I call the “thumb nail test”. Locate a young thin  branch on the outer part of the tree, and scratch some of the bark off using your thumb nail. What you are looking for is green tissue. If you find some, that’s good news. If you don’t  move further down the stem and try again. Continue this until some green tissue is found. You’ll of course reach a point where the bark is too thick to scratch off with your thumb nail. If you haven’t found green tissue by this time, the prognosis is not good.

But let’s be optimistic! I’m including links to articles explaining dormancy, caring for trees in a drought situation, and watering tips to help you nurse your trees back to health.


   University of Alabama Extension

Tree Care


   Colorado State University


   University of Illinois


More Trees Questions

Small native evergreen tree for Long Island, NY
October 06, 2008 - Hi, I am looking for an evergreen tree to plant on Long Island NY. I plan on planting it in my front yard. At maturity to about 10-15ft about 5 ft wide. Not sure about soil, the area gets good AM sun ...
view the full question and answer

Treatment of black mildew on magnolia
April 17, 2008 - I think my magnolia has black mildew. How do I treat it?
view the full question and answer

Plants for the Shade of a Pine Tree in Pittsburg
June 03, 2013 - I live in Pittsburgh, PA. My neighbor has a huge pine tree. Last year everything I planted on that side near the tree died. That part of the yard only gets morning sun, as the tree overshadows it. Wha...
view the full question and answer

Transplant shock in tulip tree in Cincinnati
October 02, 2009 - I planted a tulip tree sapling (3 feet tall at the time of planting) in May of this year and it sprouted! Unfortunately, I believe the top portion (nearly 2 feet) did not make it (the sapling only spr...
view the full question and answer

Viability of Texas madrone tree in Weatherford, TX
September 27, 2005 - I live in Weatherford, Texas (Parker County). Will a Madrone tree make it ok here and who sells them?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center