A modular wall planting system includes at least a pair of planting units each comprising a mounting structure mountable to a vertical wall surface, and a trough extending outwardly from the mounting structure and including an upwardly opening aperture, the trough defining an interior compartment divided into a first section and a second section at least partially divided from the first section, wherein the first section is adapted to receive plant matter therein, the second section is adapted to receive fluid drained from the first section, and wherein the trough includes at least one weep aperture adapted to allow water to drain from the interior compartment and the second section to an exterior of the trough. The system further comprises a fluid line extending into the interior of the trough and adapted to transport a fluid thereto, wherein the individual planting units are adapted to be secured to a wall structure in at least a partially vertically aligned manner such that a lower planting unit of the pair of planting units receives fluid drained from the interior of a higher planting unit via the at least one weep aperture of the trough.
