• Biology
  • Published 2012

Black Walnut Toxicity to Plants, Humans and Horses

  title={Black Walnut Toxicity to Plants, Humans and Horses},
  author={Richard C. Funt and Jane Martin},
The roots of Black Walnut (Juglans nigra L.) and Butternut (Juglans cinerea L.) produce a substance known as juglone (5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut trees are sometimes grafted onto black walnut rootstocks. Many plants such as tomato, potato, blackberry, blueberry, azalea, mountain laurel, rhododendron, red pine and apple may be injured or killed within one to two months of growth within the root zone of these trees. The toxic zone from a mature tree… CONTINUE READING