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
1 rating

Thursday - October 04, 2012

From: Lansing, MI
Region: Midwest
Topic: Planting, Trees
Title: Native plants for under a black walnut from Lansing MI
Answered by: Anne Bossart

QUESTION:

What native plants can you recommend that will grow in Michigan under a mature black walnut tree?

ANSWER:

Walnut trees can present a real challenge for gardeners.  Although they are great shade trees, they exude a chemical called juglone which inhibits the growth of other plants near it.  A great adaptation if you are a walnut tree and want lots of room to grow; not so great if you are a gardener with a limited amount of space!

Research indicates that the juglone increases the alkalinity of the soil, creating harsher conditions for plants nearby (the ideal condition for most plants is neutral to slightly acidic soil) so the pH of your soil will impact your success.  Also, if your soil is sandy and well drained, the effect of juglone may be less than if you have clay soil. There are publications which you will find by doing an internet search like this one by Virginia Cooperative Extension service which will be helpful.  Although not Michigan specific, Walnuts behave in a smiliar way across their native range.

Although our Native Plant Database can create lists of plants native to Michigan using the Combination Search it cannot sort according to tolerance to juglone.  However, many of the individual plant entries do indicate if a plant is juglone tolerant.  So in your search for native plants that are tolerant, you will have to check a few lists of plants like this one from Grandville, Michigan which lists non-native plants as well as native and this one from a native plant grower in Ontario (with many native plants in common with Michigan).  You can cross reference those suggestions against our lists of native plants. Many Extension offices do publish fact sheets and sometimes will have one with suggestions so do call or visit yours, but often a gardener is left to trial and error. 

Unfortunately, we can't just give you a list because every situation is different so finding suitable plants is a bit of an arduous process.

 

More Trees Questions

Identity of tree with pumpkin-like fruit in Florida
October 02, 2012 - Hello. I live in a small town called Molino FL. I was walking on the side of our road and found a tree with pumpkin type fruit on the limbs. I have been trying to figure this tree out for about 3 mont...
view the full question and answer

Dying branches on Texas Mountain Laurel from Kempner TX
September 14, 2012 - The branches on my Texas Mountain Laurel are very dry and brittle. The leaves are also starting to die. The tree has been in my yard for six years and prior to that it sat wrapped in burlap for ov...
view the full question and answer

Identification of tree with round purple leaves
May 14, 2014 - What is tne name of the purple leaf tree whose leaves are spherical? Maybe 1 to 2" in diameter? A neighbor who has moved now, had one but cut it down before i could find out or rescue it. It wasnt ...
view the full question and answer

Young oak damaged by falling tree from San Diego TX
June 27, 2012 - My neighbor's Palo Blanco tree was struck by lightning and fell over our fence and on to a young oak tree in our yard. We waited a few days to see if the neighbor would offer help, but he never did,...
view the full question and answer

Problems with Texas Ash and non-native Bradford Pear in Hutto TX
January 27, 2011 - We have planted two trees in our back yard. The first one(a Bradford Pear) died and the second one (a Texas ash) doesn't look like it's doing very well. Our back yard is mostly black clay about 1 f...
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
© 2014 Lady Bird Johnson Wildflower Center