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?

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

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 - 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 near a patio in Tennessee
January 02, 2009 - What type of tree would you plant near a patio (new home and yard) that gets afternoon sun? Thanks
view the full question and answer

Flower color under large pine tree from South Elgin IL
April 05, 2013 - I have a very large pine tree that I would like to plant some flowers under. I have hostas, stonecrop and fern, but like to add some color. What do you suggest? Thank you.
view the full question and answer

Native plants for clay soil in Lathrop MO
March 21, 2011 - My family just moved to the north Kansas City, MO area and would like to know what native species, both perennial and tree, will do best in the clay soil. It has already proven problematic as we have ...
view the full question and answer

Wildflowers that grow in woodlands
June 22, 2011 - Please tell me the names of wildflowers that grow under your oak trees in Texas. I am only familiar with those open meadow plants, not those that live under the deciduous trees. Thank you for your t...
view the full question and answer

Live Oak Suckers
March 21, 2011 - Hello, my neighbor cleared away their St. Augustine grass for mulch and plantings. Under a huge, beautiful Live Oak tree they placed a wide bed of medium gravel, almost out to the drip line. It look...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center