Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
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.
From: Portland, OR
Region: Northwest
Topic: Shade Tolerant
Title: Shade tree for Portland, OR
Answered by: Barbara Medford
We wish we knew how to explain to a tree that it should not invade foundations, buckle sidewalks or pop roots up in the garden, but that's just the way trees are. Most of their roots are within 6 to 12 inches from the soil surface, and they are relentless in their search for water, oxygen and nutrients. The following is an extract from a previous Mr. Smarty Plants question:
"As to the exact distance either should be planted from foundations or sidewalks, that becomes a matter of personal judgment. Soil subsidence around foundations is more often the result of the soil becoming too dry. It is true that tree roots will range out from their trunk as much as twice the diameter of the tree crown in search of moisture but this is usually not a prime factor in foundation damage.
In general terms regarding the planting of trees near structures, 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. The most critical area lies within 6 to 10 feet of the trunk. Paving should be kept out of the dripline and no closer than 15 feet from the tree trunk."
With that in mind, we are going to look at Recommended Species in our Native Plant Database, and find smaller trees that will result in less extensive roots but still give some nice shade to the area. Also be aware, as noted above, of the damage roots can do to sidewalks and drives in their area. These trees will all be native not only to North America but to Oregon. Native plants grown in their natural habitat will require less water, food and maintenance.
TREES FOR OREGON
Juniperus scopulorum (Rocky Mountain juniper)
Pinus contorta (lodgepole pine)
Prunus virginiana (chokecherry)
Umbellularia californica (California laurel)
Deer resistant plants for large pot in light shade in Austin
March 30, 2007 - For an Austin yard, please suggest a shrub or a mixture of plants for a 15 gallon clay pot. The area has dappled light and deer. I would prefer a deciduous plant if possible.
view the full question and answer
Grass to grow in the shade of pecan tree
December 10, 2008 - Dear Mr. Smarty Pants,
We have an enormous pecan tree in our backyard that had grass underneath the breadth of the branches, but not around the trunk. The grass isn't doing well (though we did fai...
view the full question and answer
Vines for Shade in Upstate New York
April 23, 2013 - Hello! I am looking for a non-invasive vine that will grow in heavy shade near my house in upstate New York.
view the full question and answer
Shade trees with a tap root
July 31, 2009 - I need a list of shade trees with a tap root system. I would also like the tree to grow at a medium to fast rate. I will be planting near a concrete wall and do not want the roots to do any damage to ...
view the full question and answer
Will Thunder Turf do well in shade from Iola TX
June 23, 2010 - Will the Thunder Turf do well in shady areas or is there a better blend of native grasses that would thrive better?
view the full question and answer
![]() |
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. |