Question
QUESTION: I would like to plant either an Autumn Blaze maple or a Sienna Glen maple tree in the vacinity of a small Black Walnut tree.  I have read that the Silver Maple will not tolerate the Black Walnut root juglone but the Red Maple will tolerate it.  Since both the Autumn Blaze and the Sienna Glen maples are hybreds of the Silver and Red maple I am wondering if these trees will be tolerant of the juglone or not.  I one more tolerant than the other?  How far from the Black Walnut would I need to plant them if they are not tolerant to the juglone?

Thanks,

Duane K.

ANSWER: Japanese maples --a red maple  will tolerate the juglone but silver maples will not. I would not take the chance and plant the maples well away from the walnuts say 50 feet from the roots zone of the walnut trees. The roots will extend out 1 1/2 times the width of the branches so beyond that zone there should be not problem.

---------- FOLLOW-UP ----------

QUESTION: So, if I understand you correctly, I would plant the maples about 80' from the trunk of the Black Walnut. 40' spread x 1.5 = 60' = 30' per side of the tree plus the 50' buffer.  Is that correct?  That's a long ways.  Since the maple has an expected 40' spread I am wondering if a 30' buffer would be OK instead of the 50' buffer you advise.  Your thoughts?

Thanks,

Duane K.

Answer
As long as the two root zones do not over lap you will be fine I would try to leave about 10 feet buffed between the root zones to make sure the roots will not touch. The 50 feet is a general distance from truck any thing outside the walnut root zone will be ok. I hope this clarifies the distances.