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

Tuesday - July 19, 2011

From: Austin, TX
Region: Southwest
Topic: Compost and Mulch, Watering, Trees
Title: Should Texas live oaks be mulched under drought conditions?
Answered by: Guy Thompson

QUESTION:

Should we mulch our live oaks in pastures for water retention?

ANSWER:

Live oaks are well adapted to Texas droughts, but this year is an exception.  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. Many trees have been saved in past droughts by additional  watering in late summer.  If this is not feasible for you, mulching will indeed help retain the moisture that is in the ground. A two to three inch mulch of ground bark and leaves, especially around the drip line, would be most advisable.

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.  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.

 

 

More Trees Questions

Tree for caliche soil in Cochise County, Arizona
August 15, 2012 - What trees will thrive in areas of moderate caliche soil in southeast Arizona? My property is at 4,200 feet of elevation. Thanks for your help
view the full question and answer

Need help with a Pecan tree that has been topped in Austin, TX.
July 06, 2010 - Hi Mr. Smarty Plants! I have a pecan tree on my property that was topped by the previous owners. I have searched high and low for information on how to correctly prune a tree that has already been ...
view the full question and answer

Is Carolina laurel (Prunus caroliniana) a good choice for San Juan Islands, Washington?
November 03, 2007 - What are the prospects for Carolina laurel here on San Juan Island, mixed in with thin stand of douglas fir, about 50 feet from shore, eastern exposure? Water is available but little sun because of l...
view the full question and answer

Transplant shock in Chestnut Oak in Waukesha WI
September 13, 2009 - Bought and had nursery install a 4" diameter, 16' tall chestnut oak. Watered it as instructed-every 2nd or third day-hose stream size of my pinky for 45-60 minutes. It was planted in July. Just l...
view the full question and answer

Newly planted nuttall oaks from Houston TX
November 16, 2012 - I recently purchased two Nuttall Oak Trees in Houston Texas (October). They are both 15' or taller. I planted them within 24 hours of being delivered, watered them in, staked them, and within 3-4 d...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center