En Español

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

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 - 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

Does Chilopsis linearis, var.Bubba produce seed pods? No.
October 01, 2007 - We have a really beautiful 2-year old Bubba, Desert Willow. It is already about 12 feet tall. I really have two questions. One does the Bubba form the seed pods like the other types of Desert Willows?...
view the full question and answer

Acacia tree that will grow in Louisiana
July 13, 2011 - Please tell me if there are any Acacia Trees that will grow in direct sun in Louisiana. I really want to plant some from seeds but don't which to get for zone 8. Thank you Mr Smarty Plants
view the full question and answer

Native cherry trees for Georgia
July 06, 2007 - Is it possible to grow any type of cherry in Georgia, USA?
view the full question and answer

Trees & shrubs, low water, no maintenance, disease & pest resistant
May 04, 2013 - We need few Trees and shrubs to meet the following needs: - Low Water or best with a taproot for Ground Water - Clay Soil in Steep Slopes (25-40 degrees) - Low or No Maintenance. (hillside, no trim...
view the full question and answer

Why are my Junipers turning brown in San Antonio?
May 11, 2009 - My Texas mountain cedars (junipers, I know) are turning brown, limb by limb. What is the problem and how do I save what looks like a dying tree.
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center