I cut down most of the black walnut trees near my garden, added topsoil and rototilled, but my plants still wilt. What should I do next?

Melinda: It takes at least five years for the roots, leaf litter and nut husks of black walnut trees to decompose fully and no longer pose a threat to susceptible plants. The roots of the remaining black walnuts can spread several hundred feet away from the trunk of the tree. As your new plantings mature and their roots grow, they may come in contact with remaining tree remnants or the roots of existing trees. Time will take care of the debris from removed trees. For now, consider growing resistant plants—you can find examples on extension office, university or arboreta websites. Or grow plants in raised beds lined with landscape fabric to prevent black walnut roots from invading the garden.