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
Not Yet Rated

Monday - March 11, 2013

From: Washington, MO
Region: Midwest
Topic: Erosion Control, Trees
Title: Further explanation of retaining walls and trees from Washington MO
Answered by: Barbara Medford

QUESTION:

I had a question previously about putting retaining walls across the root system of a 40' tall bald cypress tree(not like spokes on a wheel, but concentric to tree trunk). How wide can the walls be? How deep can the dirt backfill behind the walls be? How far away from the trunk should the walls stay? I am only asking how to minimize stress to the tree, not how to engineer it. My choice of words gave you the wrong direction to proceed with your answer. Please address only the plant/tree issue for me.

ANSWER:

Sorry we got so wrapped up in the rain garden issue we forgot the tree root issue. In fact, we had a reference to tree wells in our original answer and removed it because the answer got so long. For anyone interested in seeing how we goofed up, here is your previous Mr. Smarty Plants question.

Basically what you are asking about is Tree Wells. This article, we believe, actually addresses the questions you have, and much better than this mathematics-challenged gardener could. It has diagrams, a discussion of grade changes, the distance a wall  should be from a tree trunk, weep holes, etc. Since you can actually see your tree, the incline and soil type, hopefully this will answer all the questions we did not.

 

More Erosion Control Questions

Raingarden Plants for Brownsville, TX
March 14, 2014 - I'm a Landscape Architect in South Texas and I'm implementing raingardens and vegetated swales in my projects. What native plants could be used in these gardens/water runways. They would need to res...
view the full question and answer

Native plants for erosion control in North Carolina
January 29, 2009 - I have an area on the north side of my house that is a hill with about a 6:1 slope. It also has a set of steps used to get from the front of the yard to the rear yard. It is very shaded. I am havin...
view the full question and answer

Ground cover for a bank in PA
April 28, 2012 - I live in Landisburg, PA, (zone 6). I need to find some ground cover for a primarily full sun bank that is roughly 10-12' down over the embankment and up to 100' long. This area wraps around our po...
view the full question and answer

Native Streambank Plants for SE Pennsylvania
July 18, 2013 - I help manage a nature preserve in southeastern Pennsylvania. Along the stream the banks have been beaten down by a large number of visitors for their educational activities such as stream studies. Th...
view the full question and answer

Groundcover for Bonsall, CA
October 17, 2012 - I live in Bonsall, CA. (San Diego) I have 3 acres, flat and sloped that are graded dirt. (DG and sheep poop from previous owner). It is getting close to mud season and I'd like to plant winter cover...
view the full question and answer

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