A planting container is suitable for forming planting columns by using ones with the same structure three-dimensionally stacked. The planting columns are arranged around a center line parallel to the gravity direction to set up a planting tower. The planting container includes a bottom wall and a side wall. The side wall extends from the peripheral of the bottom wall and both walls define a containing space. The side wall has a planting opening communicating with the containing space. The side wall has a top end and a bottom end. When two containers with the same structure are three-dimensionally stacked by each other, the bottom end of the upper container engages with the top end of the lower container. The side wall laterally tilts towards the center line relatively to the bottom wall, so that the planting column tilts towards the adjacent column and tilts towards the center line.
