Description
The Japanese heartnut grows to 66 feet, rarely to 98 feet. Unlike other <I>Juglans</I>, it is resistant to the canker disease caused by the fungus Sirococcus clavigignenti-juglandacearum. This has led to its being planted as a replacement for butternuts in North America. The two species hybridise readily; the resulting hybrid Juglans x bixbyi (otherwise known as J. cinerea x ailantifolia or ‘buartnut’) is also resistant to canker and is likewise planted as a replacement for butternuts. Japanese walnut is distinguished from butternut by its larger leaves and round (not oval) nuts.
Our seed is from CT.
More from the Society of Ontario Canada Nut Growers
Juglone from walnut, butternut, butternut, hickory and other nut trees
Hydroxyjuglone is a nontoxic, colorless precursor that is converted into the toxic form juglone by sensitive plants and through oxidation. It is found in the vegetative buds, leaves, stems, nut hulls, and roots of the plants. Penn State Extension has a great list of trees and shrubs that are tolerant to juglone and land care practices that may give you some wiggle room when planting around these wonderful, nutty trees.