En EspaŅol

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
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

Bark damage to Tulip Tree
August 10, 2006 - I have a tulip tree planted. It is about 9-10 years old. Two years ago the tree looked as though the trunk was cracked. Maybe hit by lightning after a storm. This year the bark on the side of tree...
view the full question and answer

Dirt piled up around trunk of cypress tree in Lakeland FL
October 02, 2009 - I have a 30-40 foot cypress tree that has just started looking like it is dying..limbs on top are drooping badly. In April of this year we put probably 3 feet of dirt/clay around the bottom of it, wa...
view the full question and answer

Native evergreen trees with highest value for birds
April 02, 2007 - What native evergreen trees have the highest value for bird seed/fruit (other than Juniperus virginiana)?
view the full question and answer

Privacy screen for pool from Southlake TX
April 21, 2012 - I have a row of 7 live oaks that help block my neighbors two story house. Unfortunately, there is a gap between each tree of about 8 feet wide and 15 feet tall (from ground to the first branches/ leav...
view the full question and answer

Control of live oak suckers by cutting
July 23, 2007 - How do I control the Live Oak root suckers? At the moment we are cutting them as they come out of the ground.
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 | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center