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?


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
3 ratings

Friday - May 24, 2013

From: Austin, TX
Region: Southwest
Topic: Soils, Trees
Title: Is it OK to remove soil around oaks - Austin, TX.
Answered by: Joe Marcus


I have several oaks trees (one live oak + burr oaks) from 15'-35' in height. They seem healthy. A local arborist says they were planted too deep and that the soil around them needs to be excavated to allow room for the root collar. He said we need to remove the grass at least to the drip line. Your website said not to remove or add soil. Who is right?


In general, you want to disturb the roots of your trees as little as possible.  Since a large percentage of a tree's feeder roots can be found in the top few inches of soil, any removal of that soil is bound to disturb those roots and adversely affect the tree.  Relatively few of those roots are located near the base of the trees, but are usually concentrated near the tree's drip line.  Removing soil all the way to the drip line seems excessive, but there may be reasons for the recommendation that are not apparent to us.

In fairness, soil around the crown of a tree can cause problems.  If your soil has a high clay content, which restricts oxygen exchange to the roots, the problem can be very serious, indeed.  Some tree species are more susceptible than others to problems caused by deep planting.

The answer to your question is not cut and dried.  I would tend to follow the advice of a certified arborist, but if you have doubts, you might hire another certified arborist on a strictly consulting basis (there will be no financial advantage to give you advice one way or the other) and get a second opinion.  That involves more expense, but your landscape trees are almost always worth the expense of maintaining their good health.


More Trees Questions

pruning crape myrtle (ugh, non-native)
March 05, 2012 - We would like to plant a Dynamite Crape myrtle in front of our front window. They grow 20' to 30'. Can I trim it each year to about 15' to 20'? Should we plant it approximately 5 feet from the ...
view the full question and answer

Pros and cons of live oak leaves left on ground in Dripping Springs TX
February 20, 2013 - What are the pros or cons of leaving live oak leaves on the ground around trees or bushes?
view the full question and answer

Transplanting a native Texas Persimmon in Austin
October 18, 2008 - I have a Texas Persimmon, approx. 2.5 feet tall, growing in a 5 gal. pot. When should it be transplanted and where? How much sun? Could it grow in a larger pot for a time> Do deer like it? Thank ...
view the full question and answer

Bugs on Arizona Cypress in Bellwood IL
August 27, 2011 - I live in Illinois and have an Arizona Cypress that looks like it is dying but I notice today it has bugs inside its cone. Can you tell me why and what can I do?
view the full question and answer

Replanting members of Rosaceae family in same spot
May 23, 2007 - HI Mr. Smarty Plants We had two apple (yellow fruit) trees besides out house and they died. Is it ok to replant in the same place with other trees without being afraid something is wrong with the soi...
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.
© 2015 Lady Bird Johnson Wildflower Center