Katsura and Black Walnut

(Question)

Do you know if the Katsura tree is susceptible to juglone?

(Answer)

The allelopathic qualities  of the Black Walnut Juglans nigra do cause problems for many plants but according to research they do not cause a problem for the Katsura tree Cercidiphyllum japonicum (http://www.holmeshollow.com/living_with_walnuts.html).

Here is some more information on Black Walnut toxicity:

http://www.torontomastergardeners.ca/index.php/factsheet/juglone-and-black-walnut-a-toronto-master-gardeners-guide/

http://www.extension.purdue.edu/extmedia/HO/HO-193.pdf