Abstract: Plant container assemblies with nested growth substrates are disclosed herein. In one embodiment, a plant container assembly includes a base; an inner frame on the base; and an outer frame having a plurality of grid panels projecting from the base, surrounding the inner frame, and defining a plurality of slot regions between the inner frame and the grid panels. Growth substrates are inserted into the slot regions, and each of the growth substrates has a first side that is exposed through one of the grid panels for planting, and a second side that holds soil within a corresponding one of the slot regions.