Host an Event Volunteer Join Tickets

Support the plant database you love!

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
3 ratings

Tuesday - December 16, 2008

From: Nashville, TN
Region: Southeast
Topic: Trees
Title: Distance from existing oak trees to place paving
Answered by: Barbara Medford

QUESTION:

We are designing an expansion for an existing veterinary office and the desired side for expansion will require addition to the parking and drive aisle to the back side of the property. My question is this, how close can we install pavement to two existing oak trees (both trees have 60”+ DBH). Thank you for your time and effort in your response.

ANSWER:

An oak tree root system is extensive but shallow. The ground area at the outside edge of the canopy, referred to as the dripline, is especially important. The tree obtains most of its surface water here, and conducts an important exchange of air and other gases. Any change in the level of soil around an oak tree can have a negative impact. The most critical area lies within 6 to 10 feet of the trunk. No soil should be added or scraped away from that area. Construction activity is a great threat to trees. Do not allow any parking within the dripline or piling of materials, waste, etc. in that area.

Paving should be kept out of the dripline and no closer than 15 feet from the tree trunk. If at all possible, use a porous paving material such as brick with sand joints, open bricks, bark, gravel, etc., which will allow some water penetration and gas exchange. Even with porous paving, the area around the trunk-at least a 10 foot radius-should be natural and uncovered.

We realize these are difficult restrictions, and your construction crews will not be happy. However,  you will need to make a choice between the trees and the construction. If you fail to make provisions for the needs of the trees, even if the trees appear to have survived, they probably have only a few years before they succumb to disease or starvation. 

 

More Trees Questions

Small native trees for northern Virginia
September 27, 2011 - Mr. Smarty Plants, I am looking for a native alternative to a Japanese Red Maple in northern Virginia. I would like a small tree that I can put in my front garden that will not pose a security risk my...
view the full question and answer

Location of Alamo fungicide kit from Georgetown TX
July 03, 2012 - Where can I buy the Alamo fungicide injection kit shown in the oak wilt video?
view the full question and answer

Is California fan palm found on Edwards Plateau from Austin
January 18, 2013 - Is the following Palm, Washingtonia filifera, found in the Texas Hill Country, specifically the Edwards Plateau or Balcones Canyonlands NWR.
view the full question and answer

Tree well for partially exposed roots from Lake Kiowa TX
May 05, 2012 - Medium oak tree along lake has partially exposed roots. Can we make a barrier (what kind?) and fill the roots behind it with topsoil, compost, etc.? Tree and roots are above the waterline. Lake occ...
view the full question and answer

What shade trees have non-invasive root systems?
March 03, 2015 - What shade trees have a non-invasive root system? I am in zone 7a. Thank you, Mr. Smarty Plants!
view the full question and answer

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