The wood is prized for the distinctive colour, grain and durability. The leaves turn a beautiful yellow during Autumn. That’s it. The infamous part is the toxic chemical that gardeners regard as harmful to vegetable gardens, landscapes or surrounding groves. If you handle the black walnuts they leave stains on your hands. The roots extend 50 ft absorbing all the water, starving other plants. The walnuts inside are safe to eat, but a lot of work to clean them to be edible.