Black Locust Tree Wood Chips - Ask Extension
There was a black locust tree in my backyard that was removed and turned into wood chips. I have read that black locust can be toxic to humans but I ...
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Black Locust Tree Wood Chips #891545
Asked January 13, 2025, 9:40 PM EST
There was a black locust tree in my backyard that was removed and turned into wood chips. I have read that black locust can be toxic to humans but I want to know if putting the wood chips in my vegetable garden will leach out toxic chemicals that my vegetables will absorb. Can I use black locust mulch in my vegetable garden safely?
Multnomah County Oregon
Expert Response
Thank you for your question, Makenna. Like walnut trees, black locust trees also have chemicals in their cells which inhibit growth in other plant species. And, this Extension article explains why black locusts are toxic to animals: https://www.poison.org/articles/are-black-locust-trees-toxic-221 I can find no research addressing the safety of consuming plant tissue that has absorbed (and survived) the toxalbumins contained in black locusts. But, to be on the safe side, I recommend that you not use any mulch containing black locust material. Good luck!
