Our walnut trees must ooz a black liquid. anything under or near them have blackspots/or more covering it. Our deck railing gets black. It can be washed off mostly but not completely. Is there a way to prevent this? The flowers below the trees grow great in the summer, but now this black stuff is all over them.
Certified GKH Gardening Expert
Be cautious about planting near black walnut. They emit a chemical from their roots called juglone. This chemical is toxic to most plants. Here is an article that will help:https://www.gardeningknowhow.com/edible/nut-trees/black-walnut/black-walnut-compatible-plants.htm