I know that all walnuts and their relatives produce juglone to some degree. I would like to plant two heartnuts in my yard but would not be able to space them far enough away from established fruit trees that possible allelopathy wouldn’t be a problem. Does anyone have experience with or know of research that measured the amount of juglone produced by heartnuts? Is it enough that one would have to worry about allelopathy? More specificly, I am asking about heartnut seedlings and/or heartnut cultivars that are grafted onto heartnut rootstocks, NOT heartnuts grafted onto black walnut rootstock.
I have 5 mature heartnuts and quie a few seedlings, all on their own roots.
In close proximity, there are apples, pears, hazels, plums, potatoes, tomatoes, strawberries,
rhubarb and asparagus. I don’t know how sensitive those are, but they are doing well.
Hazelnut is jugalone tolerant
Five years ago a friend gave me a number of heartnut seedlings which their three large trees were prolific in producing (mostly thanks to squirrels). I planted them near a variety of other young fruit trees and I never thought about the juglone question. My heartnuts probably don’t have much of a future (they keep dying back winters) but I did finally ask my friends about what was growing near their trees. They said they were very close to several mature Wolfe Rivers with no issues. They just cut down the heartnuts because they got tired of the constant seedlings and nuts they weren’t that fond of. Sue