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

Tuesday - April 28, 2009

From: Rogue River, OR
Region: Northwest
Topic: Planting, Shrubs, Trees
Title: Shallow topsoil on rocky substrate in SW Oregon
Answered by: Jackie OKeefe


I want to plants some shrubs and trees. Trouble is I can't plant very deep. I have mostly rock within 5 inches. Please help.


Thank you for sending your question to us at the Lady Bird Johnson Wildflower Center. Since our mission is to inform about and promote the use of our native plants, we will point you to some resources and ideas that help you find native, well-adapted plants for your soils, topography and climate.

Okay, so you don't have a lot of topsoil. There are native species which have adapted to thrive on stony, thin-clad ground. And there are other considerations. Some are physical parameters – light, slope, moisture, exposure, wind. Others are choices – height, form, plant features like flowers, berries or thorns. Are you trying to create a screen? Do you want winter foliage or light penetration? What kinds of wildlife might find cover or forage in your landscape? Since shrubs and trees are long-term additions to the landscape, think about the long-term size and characteristics of your choices and remember the acorn thing (mighty oak trees...some things get really big).

A partial "fix" for your soil depth issue, especially if you are on a slope, is to raise and level the ground by creating small terraces. The raised end of the terrace allows you to increase soil depth, and prevents unchecked erosion. As the shrubs and trees grow more extensive root systems, they become part of the stabilizing mechanism. (When adding a new soil horizon, it is important to cultivate and mix the existing soil with the added layer so the plants roots transition into the lower soil layer.)

To search for appropriate plants, go to our Native Plants Database, select Oregon, and run a couple of searches on shrubs and trees, narrowing to your light and moisture requirements. The search results will give you a list of possible plant choices, and the individual plant descriptions should help further narrow your list. Additionally, by clicking the USDA plant symbol just below the plant name and taxonomic description, you will be taken to the USDA database, where, by clicking on Oregon on the Distribution map, you will reach a county-level map of the plant's known distribution. There are also local organizations in your area that can give you good advice on selecting specific species for your particular site. Here are some web links:

Some native plant nurseries for Oregon

Some native plant activities in your area w/The Nature Conservancy

Native Plant List of local wholesale grower Althouse Nursery


Running a search on trees and shrubs for Oregon, here are a few possible choices:

Ceanothus velutinus (snowbrush ceanothus)

Quercus garryana (Oregon white oak)

Prunus virginiana (chokecherry)

Spiraea splendens var. splendens (rose meadowsweet)

Vaccinium ovatum (California huckleberry)

Juniperus communis var. saxatilis (common juniper)




Ceanothus velutinus



Prunus virginiana


Spiraea splendens var. splendens




More Planting Questions

Starting shade-tolerant ground covers in New York
September 10, 2013 - Hi, I have seen some of the posts for shade-tolerant ground cover on the east end of Long Island and my question is process related. Now that I've identified the grasses/plants I need to keep my fro...
view the full question and answer

Improperly prepared building site in Virginia
June 24, 2008 - Hi, I have a question about planting on newly-built homesite. We just moved into a new home in DC suburbs (Northern VA) and the landscape is the worst of the builder grade. There are prickly junipers ...
view the full question and answer

Perennial blooming plants for Ashland MO
April 02, 2010 - I am beginning to create a flower bed in front of my house, I do not have a green thumb so I want to know what plants would come back yearly and I can plant now in Mid Missouri?
view the full question and answer

Failure to bloom of Esperanza from Austin
June 06, 2012 - I have an Esperanza plant. I've had this plant for over 5 years. Its in a large pot. The plant has NEVER bloomed. I fertilize maybe once a month and dont seem to be over watering, only when I notice ...
view the full question and answer

Problem with Live Oaks in Mesa AZ
March 26, 2013 - I have two Evergreen Live Oaks in central Arizona. One is flourishing and getting new spring leaves from top to bottom. Its trunk is rough, has large grooves, and the spots where I've pruned look li...
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