Yes. Black walnut trees are intelligent beings that have actually created the ideal condition for themselves through a chemical called juglone that leaches from their roots, leaves, and mulch made from walnut wood. Juglone prevents many plant species from thriving under and around the root zone of black walnuts thus giving them a stronghold on life. Nightshade family vegetables like eggplant; tomato, potato, and peppers seem to be particularly sensitive to juglone. Shrubs such as rhododendron, magnolia, and pine species are as well. Some plants will generally do fine if planted well outside the “drip zone”, or space directly under the tree. Juglone does not move efficiently in the soil, however, plants may be affected if planted downhill from a black walnut tree or in a site where a black walnut may have been removed even if it has been a few years since it’s removal. I know gardeners who have had some luck gardening around black walnuts in raised beds using plenty of compost (made without black walnut leaves, of course!). If you have no other site for a vegetable garden, as an example, you might try this system on a small scale to see if it would work for you. For a more detailed list of sensitive plants and more information about planting around black walnut trees, try the following Web sites: http://www.hort.purdue.edu/ext/HO-193.pdf and also http://www.penpages.psu.edu/penpages%5Freference/29401/29401181.html