Answer: Unfortunately, black walnut toxicity will kill your tomatoes as well as related plants such as eggplants and peppers. Certain other plants such as azaleas and rhododendrons are also extremely sensitive to the black walnut. The majority of the toxin is exuded from the roots, so cutting down the tree will not solve the problem. In relocating the garden area, keep in mind that the tree's root system often extends out from the trunk about one and a half times its height and will persist in the soil for some years. If the tree has been cut and is no longer shedding leaves and twigs over the area, however, you might consider using raised beds to avoid the roots. In addition, maintaining a very healthy soil with ample amounts of organic matter also seems to help plants in the "somewhat sensitive" range fight the toxin.
Q&A Library Searching Tips