Juglone Black Walnut Toxicity

In No Guff Vegetable Gardening we explain how black walnut trees can pose challenges in the vegetable garden.

Here’s what we say in the book No Guff Vegetable Gardening:

Some members of the walnut family give off a compound called juglone. While some vegetables don’t take notice of juglone, others, such as asparagus, cabbage, eggplant, pepper, and tomato hate it and will die or exhibit stunted growth in protest.

If you can’t move your garden away from a walnut tree, raised beds, which give good drainage, help to minimize the effect.


Steve says: We bought our current house in the spring, before the trees were in leaf, so I didn’t notice that my neighbour, Troy, has a massive black walnut tree in his backyard. The tree towers over one side of my yard too. Only after I had bought the house did I find out that the previous owner had given up on veggies because of that tree. In a state of despair, I raised the soil level and tried a veggie garden anyway, and, to date, am getting good crops.