En Espa—ol

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 - June 07, 2011

From: Austin, TX
Region: Southwest
Topic: Watering, Drought Tolerant, Trees
Title: protecting native trees during drought
Answered by: Guy Thompson

QUESTION:

We are very concerned about our mature live oaks and cedar elms because they are so stressed due to the drought. We have lost several of our mountain juniper and I really don't want to lose our more valuable trees. I know slow deep watering is best, but how much water is that? Can you give me advise on how to water them that will do the most good?

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. 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, rees 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 Watering Questions

Drip irrigation and uneven distribution
June 29, 2012 - Subject: Drip irrigation and uneven distribution. Iíve installed drip irrigation in an area of mature shrubs (St. Johnís Wort) in Austin. These have previously received about ĺ inch of water once ...
view the full question and answer

Leaf fall from Cedar Elm planted in clay
August 17, 2008 - I saw the answer to leaves falling off a cedar elm planted in clay. However I planted a Cedar Elm in my back yard. I dug a hole in the grass then planted and put grass back on top. I water every other...
view the full question and answer

Repotting of lemon cypress for drainage
October 26, 2008 - Hi, I bought a lemon cypress tree in a nice tin, It is in Plastic and the bottom has about 1.5" of water with no drainage in the plastic or tin. It will be kept inside. Does the plant need to be in...
view the full question and answer

Xeric landscaping walls in Mansfield TX
November 15, 2009 - We have two stone, concave 10 ft. high entry walls to our private street. These are each 20 ft. in length and face the west. What xeriscaping accent plants would you recommend. Also, should we crea...
view the full question and answer

Mulching tree root in San Angelo, TX
April 02, 2014 - San Angelo, Texas is in a drought stage. Will it help our trees to mulch the base of them?
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