Juglone and Walnut Trees
Does 'Carya texana' produce enough juglone to kill rhododendrons? It's a black hickory. Just wondering, as I came across somewhere saying all walnut species can produce it and harm rhododendrons. I don't know how true this statement is, as it says the black walnut is the tree that produces the most juglone of the walnut species. Is it only the black walnut you need to be worried about?