Using black walnut leaves for mulch

I?ve been reading about the benefits of using leaves as mulch. We have a lot of black walnuts on our property?is it okay to use their leaves as mulch?

?Eileen Fraser, Niagara-on-the-Lake, ON

Do not use the leaves of black walnuts (Juglans nigra) for mulch. Like the tree?s roots, bark and nut hulls, they contain a toxin called juglone that can adversely affect other plants. Though the leaves have a lower toxicity level than the ground under the canopy near the roots and where the nuts fall, using them as mulch would still jeopardize other plants. Just take the leaves right out of the garden and find other types to mulch with (midnight raids on your neighbours? recycling bags are always useful).

?Marjorie Harris, Editor at Large