Systems, methods and devices are provided that include one or more modular planter curbs, wherein each modular planter curb includes a concrete unit that has a back side that is substantially upright, that has a front side that tapers from a wider lower portion to a narrower upper portion, and that has a height not exceeding 24 inches. The concrete unit may include precast concrete, cast stone, and/or precast stone. Each modular planter curb also may include connector points, and connector hardware may be used to interconnect the plurality of modular planter curbs at the connector points. In some embodiments, a modular planter curb may be selected from the group comprising a bench curb, a backrest curb, a daybed curb, a transition curb, a straight curb, a curved curb, an annular arc curb, and a full annular curb. Numerous other aspects are provided.