Explore Plants

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
    
 

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

PVC pipes for irrigation in ground in Austin
August 19, 2009 - Mr. Smarty Plants,What are your thoughts on installing PVC pipes into the ground around trees and shrubby trees? A classmate's grandmother had a pipe pushed or pounded into the ground near her speci...
view the full question and answer

Watering live oak trees from McAllen TX
December 24, 2012 - What are the watering requirements for live oak trees in deep south Texas? How often and how many inches to be applied? One pop-up spray sprinkler spaced approximately fifteen feet away from each tr...
view the full question and answer

Irrigation of landscaping project after 1 year in San Antonio
November 10, 2010 - Hello, I am working on a project in San Antonio where the following vegetation types have been specified: cedar elm, bald cypress, 'Tifway 419' bermuda grass, mountain laurel, esperanza, and lantana...
view the full question and answer

Care in planting native Shumard oaks
April 16, 2008 - I am going to plant 3 shumard red oaks on the west side of my property. The land is basically rocky. What should I put in the holes to help the tree grow?
view the full question and answer

Oak tree with browning leaves in Brenham TX
August 16, 2011 - I have a large oak tree in my small back yard. I also have a sprinkler so the tree has been receiving some water. Nevertheless, some of the leaves are turning brown in patches. Would drip watering ...
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.