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
Not Yet Rated

Thursday - January 14, 2010

From: Hudson, FL
Region: Southeast
Topic: Invasive Plants
Title: Will Arborvitae (Thuja occidentalis) roots cause problems in a leach field?
Answered by: Nan Hampton


A new neighbor is concerned my Arbovitae's root system will go into his leach field. His house has been there also for the same amount of time as the tree and the field. The tree is 45 years old. Do I have to worry?


Well, I think if your house and your neighbor's house with its leach field have been there for the 45 years that your  Thuja occidentalis (arborvitae) has been growing and there hasn't been a problem so far, then there isn't likely to be a problem.  Virginia Cooperative Extension has an article, Planting on Your Septic Drain Field, that gives guidelines about distances for planting trees from leach lines.  The article classifies several trees according to their aggressiveness for invading a drain field.  Unfortunately, arborvitae isn't one of the species listed, but I couldn't find any indication that arborvitae is considered to have particularly invasive roots.  The article recommends a distance of 25 to 60 or 70 feet from the leach field depending on the aggressiveness of the tree.  If your arborvitae is closer than 25 feet to your neighbor's field and he is exceptionally worried about its roots invading, you should suggest that he put in a root barrier (see the Virginia Cooperative Extension article above) between his field and your tree.


More Invasive Plants Questions

Is it OK to plant Huisache in southern California?
June 15, 2009 - We have a wonderful huisache growing on a very dry rocky/dusty slope. It has now sprouted babies and we are delighted because we have room for several more on this slope. I have some room on our front...
view the full question and answer

Native replacement for bamboo from Houston
May 21, 2013 - I've read one reply where you do not advise using Bamboo as a privacy fence plant. What do you suggest in its place? The suggestions on the one I read will not work for me. Your suggestions were My...
view the full question and answer

Controlling Triadica sebifera (Chinese tallow tree)
July 20, 2013 - We are trying to remove Chinese tallow trees from the lake bed on Lake Buchanan. We cut them down, but they grow back from the roots. They are very hard to dig out. Do you have any suggestions for how...
view the full question and answer

Removal of non-native invasive Ligustrum japonica from Austin
February 14, 2012 - I bought a house that I am slowly turning into a native garden, but as a teacher, I have a really small budget. One entire border of my backyard (30 feet) was planted with evil Ligustrum japonica. I l...
view the full question and answer

Horsetail Rush invasive in Santa Monica CA
January 16, 2012 - Mr. Smarty Plants: I live about 3 miles from the beach in the Santa Monica area and have an 18inch deep planter area in my backyard that is adjacent to my garage. I like the look of horsetail rush. I...
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