Black walnut kills plants. I first heard this statement many years ago. Occasionally, I still hear some version of this claim: Black walnut engages in warfare by releasing a chemical into the Cold Hardy Avocados: Guide to Cultivation and Varieties Florida Fruit Geek Grow beans in a jar it's easy! UBS Family Black Medic, Medicago lupulina Wisconsin Horticulture If I could only cook one dish for a vegan skeptic