A vegetative roof system includes modules for holding growth media in which plants can grow. The modules can communicate with each other, sharing moisture/nutrients, increasing airflow to enhance plant respiration, allowing soil-borne animals/insects to travel between modules, etc. A rooting channel and/or a scalloped sidewall allow the roots of plants in the module to extend to adjacent modules. Alignment notches in sidewalls facilitate alignment of rooting channels between adjacent modules. Vertical zones help facilitate placement of abutting modules flush with each other. The rooting channels may be formed at the vertical zones to enhance continuity between and among modules. Sheet inserts can control rooting between modules and restrict undesired spillage through rooting channels (temporarily if biodegradable). Module inserts help control the quantity and depth of growth media, affecting module weight and rooting levels. An elevated connector can secure two or more modules together using downwardly-radiating prongs.
