Ornamental grasses and black walnut trees
Both of these grasses are listed as tolerant of juglone, the substance that many plants can't tolerate. Plants within 50 to 100 feet of a mature black walnut will be affected by juglone. The other factors to consider are competition for water and the amount of shade the tree is creating.
Other grasses tolerant of walnut are blue oat grass, blue fescue, 'Karl Foerster' feather reed grass, little blue stem, and switch grass.
Click on these links to find plants that tolerate walnut:
- The Best Plants for 30 Tough Sites
- Missouri Botanical Garden Plant Finder (notes in each plant's description whether it tolerates walnut)