Vegetative systems are described. In one embodiment, a vegetative system has substantially distinct or separate zones or layers in which each zone or layer performs primarily one of the functions of water retention, a growth medium for vegetation, and weed suppression. An upper may comprise coarse aggregate and serve the primary function of weed suppression; a middle layer may comprise a mixture of coarse aggregate, fine aggregate, and fine organic material and serve primarily as a growth medium for vegetation; and a lower layer may comprise high-density hygroscopic material and serve the primary function of water retention.