Eastern black walnut requires consistent moisture, especially during its establishment phase. Water deeply and regularly once a week during dry periods. Avoid waterlogged soil, as this can lead to root rot.

Mature trees are more drought-tolerant but benefit from occasional deep watering in prolonged dry spells.

Prune eastern black walnut primarily to remove dead, damaged, or crossing branches. The best time to prune is during dormancy in late winter to minimize sap bleeding.

Avoid heavy pruning, as it can affect nut production and tree health. Make clean cuts close to the branch collar.

Propagation is typically done through seeds, which require stratification (a period of cold, moist conditions) to germinate.

Collect nuts in the fall, remove the hull, and store them in moist sand or peat moss in a cool location. Scarification of the hard seed coat can also improve germination rates.

Repotting is not applicable for Juglans nigra as it is a large tree typically grown outdoors from seed or transplant. If for some reason a young seedling is in a container, repot it into a larger container in the spring as soon as its root system begins to fill the current one.