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southerngardening24

are black walnut tree leaves bad for plants?

I have heard that certain plants shouldn't be planted near a black walnut tree. Are their fallen leaves harmful to plants? Thanks.

Comments (5)

  • morz8 - Washington Coast
    9 years ago

    There are plants sensitive to the juglone in walnut, and other that are tolerant to it. The largest concentrations of juglone are in the walnut's buds, nut hulls, and roots but leaves and stems do contain a smaller quantity.

  • NHBabs z4b-5a NH
    9 years ago

    Rhododendrons and tomatoes are two of the most common that aren't tolerant, but if you google "juglone tolerance" plant lists will come up.

  • southerngardening24
    Original Author
    9 years ago

    Thank you both!

  • jayco
    9 years ago

    If the tree is near enough to the sensitive plant for its leaves to fall on it, the growth can be stunted. For example I have three double file viburnum all planted at the same time 10 years ago. The one near a black walnut (although it is at least 10 feet outside its drip line) is sbout half the size of the other two. Good luck!

  • southerngardening24
    Original Author
    9 years ago

    Thanks everyone for the info! I am investigating this further!