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?

Share

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

Sunday - August 01, 2010

From: Mt Pleasant, MI
Region: Midwest
Topic: Shrubs
Title: Dogwood under a black walnut in Mt.Pleasant MI
Answered by: Barbara Medford

QUESTION:

Can I grow red or yellow twigged dogwood near a black walnut?

ANSWER:

You can plant a Cornus sericea (redosier dogwood) anywhere you choose; whether it will thrive or even live more than a year or so under a Juglans nigra (black walnut) is another question entirely. Both are native or near your area of Isabella County, in central Michigan, USDA Hardiness Zones 4a to 5a.

The problem, as you may know, is a characteristic of black walnut to emit juglones, substances intended to discourage or prohibit competition from other plants. We found an excellent article from  Virginia Cooperative Extension Black Walnut and Allelopathy which fully explains this procedure. Even plants some distance away can be affected because every part of the tree exudes the juglones, including roots which may extend 3 times the size of the crown. However, this same article had a chart of plants that were resistant to the effects of allelopathy, including trees and shrubs. On this chart of resistant plants "dogwood, flowering" was listed. There are 14 members of the genus cornus, dogwood, native to North America, and all of them appear to us to be flowering including Cornus sericea (redosier dogwood).

Therefore, we are assuming that it would indeed be okay to plant the dogwood in the area of the black walnut. If the dogwood does fail to thrive, you can always blame moles or bugs or too much rain or too little rain, just don't blame the researchers or Mr. Smarty Plants. 

From the Native Plant Image Gallery:


Cornus sericea

Cornus sericea

Juglans nigra

Juglans nigra

 

 

 

More Shrubs Questions

Hollies not retaining leaves in Tulsa
August 10, 2008 - I have Little Red Hollies that have lost their leaves, some areas being bald. They are also not full - you can see through them. These were planted in this condition Spring of '08 and have been wat...
view the full question and answer

Noise reduction hedge from Austin
April 17, 2013 - Noise reduction hedge row in Austin. We back up to a very busy street and need a fast growing noise barrier. In a similar post for the Houston area, you recommended Gordonia lasianthus -loblolly bay. ...
view the full question and answer

Evergreen shrubs or small trees for privacy in Cumming GA
May 11, 2010 - I have a eight foot fence in my back yard. My back yard is full of trees and is very shady in the late spring and summer months and in the winter when the leaves fall is very bare. I am looking for...
view the full question and answer

Suitability of Carolina Cherry Laurel for Bulverde TX
October 24, 2012 - The local Home Depot is selling Carolina Cherry Laurel Trees. They look beautiful. Is this a good tree for Bulverde TX..20 miles north of San Antonio? Can it survive? Will it be a high maintenance...
view the full question and answer

When does Ziziphus obtusifolia leaf and flower in Austin?
March 22, 2010 - Hello Mr. S.P., Do you know when the Texas buckthorn, Ziziphus obtusifolia (I believe), flowers (and leafs out) in Austin? Is there one at the Wildflower Center?
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center