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?

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
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

Wednesday - July 13, 2011

From: Harlingen, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Treating suspected drought-stressed live oak
Answered by: Guy Thompson

QUESTION:

I have a live oak with excessive leaf drop - it was planted approx. 20 year ago surrounded by heavy pavers. very little grass - I did not plant the tree - I have noticed in the last few years the drop increases - the oaks I have in the back yard only shed during the winter, we have long hot summers. I can removed the pavers. Thank you

ANSWER:

There is no question that even old, well-established trees are going to need some extra help during the kind of drought we are having right now. If the pavers around your tree are set close together, water permeation may be sharply curtailed.  Mr. Smarty Plants recommends that you remove as many of the pavers as possible, right out to the drip line of the tree. Replace the pavers with 2-3 inches of mulch to slow the evaporation of soil water.

Many trees have been saved in past droughts by additional  watering in late summer. As the underlined article suggests, professional arborists suggest deep watering, and the amount of water applied would depend on your soil type, e.g., rocky or clay.  The trees might also benefit from additional fertilization.  Furthermore, trees suffering from drought stress are often more susceptible to insect and fungal attack.

This University of Illinois Extension website Dealing with the Drought affirms that watering even drought-resistant trees like the oak is essential. It points out that a 90 ft. oak tree will be a lot worse to lose than annual flowers or vegetables. We don't recommend watering at the base of the trunk, but watering farther out, with a hose or sprinklers, probably about every two weeks. An excerpt from this website will tell you why:

"Our 90-foot oak example could have roots at least 40 feet beyond the tree’s
drip-line. The same goes for most shrubs. So, apply water at the tree or
shrub’s drip-line, not at the trunk."

Those roots may be pretty deep, and part of the protection of the trees, but much of the root system is in the top 12 inches of the soil. So, putting the water out there helps to avoid fungus and rot at the base of the trunk.

 

From the Image Gallery


Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

More Trees Questions

Shade tolerant plants for Waynesville MO
April 09, 2013 - We moved to Waynesville, MO (gardening region 6) and when we bought our house there was a nice looking gardening area in front of the house. It is shaded moderately by a Redwood Tree and was "occupie...
view the full question and answer

Flowers under pine trees from Elkhart Indiana
May 02, 2013 - I have a number of pine trees at the back of my lot and would like to plant flowers under the tree. What can I plant?
view the full question and answer

Noise reduction hedge row in Houston
October 01, 2009 - We live just one house back from the freeway and would like to plant a fast growing noise reduction 'hedge row' - close growing to 20-40 ft. We are looking at Leyland Cypress but know they aren't n...
view the full question and answer

Fasciation on Texas Mountain Laurel
November 21, 2012 - Do Texas Mountain Laurel normally have a staghorn looking growth hanging on them after blooming in addition to the seed pod clusters or could this be a mutation?
view the full question and answer

Daily water absorption of live oak from soil
December 04, 2003 - How much water does the live oak absorb from the soil per day?
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2015 Lady Bird Johnson Wildflower Center