Contact Us Host an Event 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
2 ratings

Thursday - March 10, 2011

From: Austin, TX
Region: Southwest
Topic: Trees
Title: Roots in mulch around Live Oak in Austin
Answered by: Barbara Medford

QUESTION:

I have a 20 yr old Live Oak that has about 6-8 inches of mulch buildup around the base (I had landscaped around it). I went to break up the mulch to remove it from the base of the tree, but found it was packed with roots, that I will have to break up with an ax to clear the tree base. Will this harm the tree? Should I leave it as is, or is the buildup around the tree base a greater risk to the tree?

ANSWER:

First and foremost, we never recommend piling mulch, dirt or even fallen leaves up around the base of any tree. This can encourage fungi and provide harbor for insects. Mulch under a tree is not a bad idea because this helps protect the roots from heat and cold damage and can suppress weeds. Mulch ON the tree is not good. Get it off, and keep it off.

Do not, please, take an axe to this tree, This is a proven way to invite Oak Wilt into your Live Oak. Any damage to a tree is going to produce sap flowing, and the Nitidulid beetle, carrying the spores of Oak Wilt on his body, will come swarming in to drink that sap. Live Oaks are the most vulnerable trees to Oak Wilt, and this is the worse possible time of the year for them to be exposed. Oaks should be pruned only in the hottest and coldest times of the year, when the beetle is not active. See this website on the Texas Oak Wilt Information Partnership for more information.

Tree roots need oxygen. Putting such a thick layer of mulch over the root area probably forced the growth of roots trying to get to some air. For the time being, we would suggest you leave those exposed roots alone, and mulch no deeper than about 2 inches, with zero inches up against the trunk.

 

More Trees Questions

Using Coffee Grounds under Live Oaks in Texas?
March 18, 2016 - Can you add coffee grounds to live oak tree?
view the full question and answer

Wilting American Smoke Tree in Texas
April 21, 2013 - I planted a young American smoke tree last fall (mid-November) and it put out a good show of tentative new leaves this spring. Then to keep the tree form I clipped some little shrubby start ups at the...
view the full question and answer

What are the grey-green plants on oak trees in San Marcos, TX?
March 12, 2011 - The oak trees in the neighborhood in San Marcos, TX, are covered with clumps, or balls, of gray/green fluffy-looking plants. they remind me of bromeliads. You can pull and knock them off; after wind ...
view the full question and answer

Texas wild olive for Summerfield FL
January 17, 2013 - I want to buy a Texas Wild Olive for my home in Summerfield, Fl. My landscaper brought me a regular olive tree saying he had never heard of a Texas Olive Tree in our area. I have looked on line withou...
view the full question and answer

Are poplar trees and willows safe for animals to eat
August 04, 2008 - poplar trees and willows, are they friendly for farm animals to consume leaves?
view the full question and answer

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