Native Plants
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Wednesday - March 18, 2009
From: Portland, OR
Region: Northwest
Topic: Shade Tolerant
Title: Shade tree for Portland, OR
Answered by: Barbara Medford
QUESTION:
Looking for shade tree for Portland, Oregon, with non-invasive root system. House will be 20 ft away, with basement.ANSWER:
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)
More Shade Tolerant Questions
Evergreens for privacy in VA
June 24, 2012 - I need fast growing evergreens or large shrubs, flowering or non-flowering, for privacy. They will need to flourish among large oak and hickory trees that are 75 plus years old. We don't want to dama...
view the full question and answer
Flowering shrub for part shade in Southern California
September 10, 2009 - What shrubs would be able to flourish in morning shade but deal with afternoon sun and 90 plus degrees in the summer months in Southern California? I would like a shrub that is about 5 ft. tall and 3 ...
view the full question and answer
Plants for border garden in shade in Austin
March 15, 2009 - Need suggestion for what to plant in a border garden. We live in northwest Austin and the garden is north-facing and shaded. Currently are oleanders but they don't get enough sun. Also growing are...
view the full question and answer
Low evergreen drought-resistant shrubs for area in partial shade
January 03, 2014 - I promised my mom to help her with some new plants for her house, so here goes. She lives near Waco on Blackland clay soil. The problem area is right in front of the house. It only receives a few hour...
view the full question and answer
Native grasses for bare shady spot in Austin
July 01, 2008 - My back yard is shady from old Arizona Ash trees. What native grasses can I plant in bare areas caused by my dog?
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |