The first garden I started was under black walnut trees, and I didn't know anything about them at the time. By sheer luck I managed to plant things that would grow there, and there are actually a lot of choices. The only thing I have had to move as the trees have gotten bigger is my tomato plants. Right now my gardens near the black walnut trees contain the following: an old old honeysuckle shrub (not sure what kind) and a gigantic double-trunked cedar tree, Tiger Eye sumac, scotch pine, lilacs, hosta, bleeding hearts, jack-in-the-pulpit, hydrangea, clematis, daylilies, sedum, viola, ferns, solomon's seal, heuchera and tiarella, astrantia, lady's mantle, Jacob's ladder, celandine poppy, anemone, Culver's root, Bowman's root, toad lilies, turtleheads, primroses, amsonia, goatsbeard, foxglove, astilbe, prairie smoke...that's all I can remember for now. I have false indigo not too far away, but I know for sure that wouldn't work if it were any closer. I also tried and failed with rodgersia. Yes, the leaves and nuts are messy, but as you can probably tell my garden is sort of woodland-ish; I actually get worse litter from the cedar tree. I scoop up all of the walnut and cedar litter and spread it out where I don't want anything to grow (like along the alley where I can't plant anything, but weeds and tree seedlings like to cause problems). In the photo below, the black walnut trees are right behind where I stood to take the photo.
