Seed pods from these trees create a mess when they drop. Bark is grey-black and deeply furrowed. Very prone to heavy aphid infestation, as the aphids feed they excrete a honeydew that can damage paint on cars. Black walnut roots give off a toxic chemical that can inhibit the growth of adjacent trees. Enjoys full sun and deep watering every 10-14 days. Not temperature sensitive or prone to disease, does not need protection.