A molded synthetic resin nursery box B comprises a grid member 2 dividing the box into individual compartments 3 communicating with each other through side wall apertures 23. A wavy bottom plate 12 of the box has drainage holes 13 therein, and the grid member side walls are notched at their top edges. Adjacent boxes are connected by engaging projections 4 on one box with mating slots 5 on another box. The planted boxes may be installed on a horizontal surface whereby the grid members bear the weight of a person walking thereon to prevent trampling and plant damage, or vertically by mounting the boxes in assembled, stacked frames 100 filled with soil. Alternatively, the grid members may be made separate from the bottom plate and side wall 11 bases, and snap-connected to pedestals 14 upstanding from the bottom plates after planting.