Explore Plants
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.
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
Wednesday - July 22, 2009
From: Harrisville, MI
Region: Midwest
Topic: Trees
Title: Planting under Walnut Trees in Harrisville, MI.
Answered by: Anne Bossart
QUESTION:
I have 2 50+ yr old Black Walnut trees in Northern Michigan (zone 4). I am planting a new bed (raised of course) and was considering adding a hydrangea. I am curious if this will thrive due to the juglone caused by Black Walnut or if I should be ok. Some sites say YES and some say NO.ANSWER:
You didn't mention if you are building a raised bed in the root zone of the walnut nor how deep it is. Most of a tree's feeder roots (which need water, nutrients and air) are in the top 36 inches of the soil, no matter how big the tree is. So any time you change the existing grade and cover those roots with soil, you are putting the tree in jeapordy.
You also didn't mention what type of hydrangea you are planning to plant ...and hydrangeas don't appear to be juglone tolerant. Some native shrubs suitable to your area that are juglone tolerant include:
Amelanchier arborea (common serviceberry)
Hamamelis virginiana (American witchhazel)
Hypericum prolificum (shrubby St. Johnswort)
Physocarpus opulifolius (common ninebark)
Rhus aromatica (fragrant sumac)
However, from personal experience (I have a property at approximately the same latitide as you, on the eastern shore of Lake Huron, in Ontario) I have found that many things grow under my two very huge old (one is over 100 years old) walnut trees that should not. I wonder if the soil conditions this far north have a diminishing effect on juglone. So if you are planning to plant a hydrangea that is native to Michigan and suited to the garden conditions and plant community existing on your property, it is probably worth a try.
More Trees Questions
Propagating magnolias from Springtown TX
July 07, 2011 - I am trying to find out how to plant Magnolia tree seeds and what has to be done with them prior to planting, if anything and what type of soil to use.
view the full question and answer
Native trees for Alameda County, California
May 14, 2010 - I looking for trees native to my area to plant on my property. I am located in Livermore CA.
view the full question and answer
What are the grey-green plants on oak trees in San Marcos, TX?
March 12, 2011 - The oak trees in the neighborhood in San Marcos, TX, are covered with clumps, or balls, of gray/green fluffy-looking plants. they remind me of bromeliads. You can pull and knock them off; after wind ...
view the full question and answer
Thornless honeylocust trees for Taylor TX
September 21, 2009 - I live in Taylor, Williamson County, in central Texas and I am interested in selecting trees for my backyard. I can't really explain (it may be my Midwestern roots), but I would like to plant three t...
view the full question and answer
Austrian pine in landscape in Denver CO?
May 30, 2009 - I'm relandscaping my yard and want to use all or mostly native plants, as I want to create a wildlife. My landscape designer has indicated she wants me to use Austrian Pine in as a specimen tree in t...
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. |
