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

Fruit-bearing crabapple for Austin, TX
January 07, 2007 - Is there a fruitbearing crabapple that will live in Austin. If so, what soil type is required?
view the full question and answer

What is the scoop on dwarf cedar elms?
April 29, 2009 - Several years ago, I purchased a small plant from a San Antonio wholesaler that was identified as a "Dwarf Cedar Elm." My brother had also purchased a few from there. No one there knows anything a...
view the full question and answer

Possibility of symbiotic relationship between cedar elm and ashe juniper
November 14, 2006 - Is there a symbiotic relationship between cedar elm and ashe juniper? We have a small ashe juniper sapling and a small cedar elm sapling growing near each other (actually, we planted the juniper 2 yea...
view the full question and answer

Dying branches on Texas Mountain Laurel from Kempner TX
September 14, 2012 - The branches on my Texas Mountain Laurel are very dry and brittle. The leaves are also starting to die. The tree has been in my yard for six years and prior to that it sat wrapped in burlap for ov...
view the full question and answer

Low maintenance replacement garden in Ashburn , VA
April 30, 2009 - We live in Ashburn, VA (Northern VA). Our house is 10 years old and the contractor grade plants have died. We are planning on digging everything up and re-doing the landscaping in our front yard - r...
view the full question and answer

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