Vegetable killer

Asked October 13, 2019, 3:23 PM EDT

Hello, I learned while ago that Black Walnut produce a chemical that does not let vegetables grow. Is black walnut the only tree/plant that does this or there are others like other nuts or fruites with large seeds like Peach? I do compost all fruit leftovers including seeds and skins and then use the compost for my vegetable garden Please advise.

Montgomery County Maryland

1 Response

Hi- juglone is the compound that is released by walnut tree roots and seems to weaken plants growing in the vicinity. This has been observed in vegetable gardens with tomato in particular but there is not a lot of research-based information on the topic.

Peach, cherry, and plum pits contain compounds that can release tiny amounts of hydrocyanide. Composting breaks down the pits over time and renders them harmless to people and plants. All vegetable and fruit seed and peels can be composted.

We suggest not composting store-bought potato and onion/garlic family crops (all vegetatively propagated) as they can carry disease organisms (late blight of potato and white rot of onions and garlic) even when tubers and bulbs appear symptomless.
Jon