Rent Shop Volunteer Join

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 - 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 Drought Tolerant Questions

Drought & Deer Resistant Shrub for Shade in Medina, TX
June 14, 2013 - We are dedicated to native plants in Medina, but are desperate to find a drought and deer resistant shrub for shade. Would we be too far off base with an oleander bush? We know birds and most butterfl...
view the full question and answer

Low maintenance, drought tolerant, native plants for school garden in Round Rock
March 30, 2006 - Our school is about to plant a memorial garden but need very drought tolerant plants and flowers as the schools water very little during the summer months. What would you suggest? The district does ...
view the full question and answer

Shade Trees for Bullhead City, AZ
August 12, 2014 - We have a patio with 2 old (unused) fire pit cut-outs; about 4 ft wide each. The cut out is not lined with concrete or brick: just rimmed with the concrete on all sides. The center of the cut-outs i...
view the full question and answer

Leaves dropping on evergreen sumac in San Antonio
January 11, 2012 - I have a large evergreen sumac in my back yard that started off as a small shrub 10 years ago. This summer the leaves turned red and now have dropped off. Is the plant dead? It sent out two smaller pl...
view the full question and answer

Groundcover for Austin yard
March 08, 2012 - My main goal is to cover my yard with a "grass" or groundcover that can handle the Texas heat, predicted long drought and some dog paw traffic (without going dormant/brown in the winter). I don't n...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.