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

Friday - September 26, 2008

From: Aledo, TX
Region: Southwest
Topic: Trees
Title: Distance from wall to plant Eastern red cedar
Answered by: Nan Hampton


I want to plant a row of Eastern red cedar on the high side of a 2 to 2 1/2 ft large Pavestone block retaining wall, preferably as close to the wall as possible. We have put maybe 4-5" of gravel behind this wall to facilitate drainage, and this should deter root growth toward the wall. How close to the wall can I safely plant these trees? Thank you much.


Juniperus virginiana (eastern redcedar) generally grows to around 40 feet high, but can grow as tall as 90 feet. Its width at maturity can be 8 to 20 feet wide.  How close to your pavestone wall you choose to plant should be guided by the range of any lateral roots and width of the mature tree.

The US Forest Service database says:  

"Eastern redcedar generally has a shallow, fibrous root system, though roots of mature eastern redcedar trees may penetrate 25 feet (7.6 m) and lateral roots may reach 20 feet (6 m).  Eastern redcedar seedlings have penetrating taproots and may later develop a lateral taproot system.  The deep, early taproot is usually replaced by an extensive, shallow root system with age.  Even 1st year seedlings begin developing a long fibrous root system, often at the expense of top growth.  The root system may be deep where soil permits, but on shallow and rocky soils eastern redcedar roots are very fibrous and tend to spread widely.  The development of a lateral taproot with age may also enable eastern redcedar to persist on outcrops and shallow soils."

The US Forest Service Silvics Manual says that the soil condition determines whether the tree develops a deep tap root or spreading lateral roots.  In thin rocky soil fibrous lateral roots will be predominant; but, if the soil permits, the root system may be a deep penetrating tap root.  So, if your soil is good, you shouldn't have great concern about lateral roots.  

You should probably not plant the trees a distance from your wall that is less than half the width of the mature tree.   Kansas Forest Service recommends a planting spacing for redcedars of 6 to 10 feet and University of Missouri Extension recommends a spacing of 8-12 feet.

Cultivars have been developed that are smaller; for instance, according to the University of Connecticut there is a cultivar, 'Emerald Sentinel', that is a pyramidal, columnar shape that grows to 20 feet high and only 8 feet wide. If this tree sounds as if it is tall enough for you, it could probably be planted 3 to 4 feet from your wall.

Juniperus virginiana

Juniperus virginiana

Juniperus virginiana

Juniperus virginiana




More Trees Questions

Shade trees for Spring TX
August 17, 2011 - Dear Mr.Pants, our west-facing backyard in Spring, Tx, is unbearable in this Summer's heat. Neither us nor the neighbors has any backyard trees established yet, as the subdivision is pretty new. C...
view the full question and answer

How close can house be built to live oak from Austin
May 30, 2012 - We have a healthy 21" live oak tree on our lot and are planning to build a home in Circle C subdivision in southwest austin. The home foundation will be within 15' of the large live oak. Need your h...
view the full question and answer

Why is my 3 year old Redbud not flowering in San Marcos, TX?
March 24, 2010 - My Cercis canadensis var. mexicana, purchased at the Lady Bird Johnson Wildflower Center, is 3 years old, very robust, but has never bloomed. Any explanation?
view the full question and answer

Shrubs and trees to protect beehives in Godley TX
April 06, 2010 - Dear Mr. Smarty Plants, Is there a (relatively) fast growing native small tree or large shrub (NOT cedar) that tolerates Johnson County clay, full sun, sometimes damp and sometimes dry soil with no...
view the full question and answer

Problems with new transplant non-native weeping willow from Washington DC
September 10, 2012 - I replanted a very young BABY weeping willow tree and now it looks as if the leaves are drying up like it is dying. I know that it could also be in shock from the new transplant or it can be dying ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center