A modular vertical cultivation wall system comprising: at least two posts, at least two planter shelves a pipe, a seed/plant root retaining matrix, and irrigation fluid, wherein; each post is elongated, vertically anchored to at least one retaining surface and comprises at least one web and at least two flanges; each planter shelf is elongated and comprises: a top wall flange, a bottom wall flange, a full height side wall connecting the top wall flange and the bottom wall flange, a short side wall and two endcaps walls; the opposing ends of a first horizontally oriented planter shelf are disposed between the at least two flanges of each of the two vertical posts; the opposing ends of a second horizontally oriented planter shelf are disposed between the at least two flanges of each of the two vertical posts retaining the first planter shelf, and wherein the at least two planter shelves are configured to slide downwardly into a position in which the bottom wall flange of the second planter shelf couples with the top wall flange of the first planter shelf by at least one reciprocating mechanical key; the endcaps' walls coupled to a top surface of the bottom wall flange at both ends of the first and second planter shelves and to their side walls define a fluid irrigation reservoir that is open to the above; and in which system piped fluid is configured to directly flow to a fluid irrigation reservoir of a planter shelf through an opening in the web of one of the vertical posts and exit the fluid irrigation reservoir through at least one opening (24, 39) in a bottom wall of the fluid irrigation reservoir; or piped fluid is configured to indirectly flow to a fluid irrigation reservoir of a planter shelf via a pressurized pipe extending between coupler pipes in the webs of the at least two posts, said pressurized pipe having at least one emitter nozzle and being disposed at the bottom of the fluid reservoir of the planter shelf, wherein one coupler pipe delivers fluid to the pressurized pipe while the other coupler pipe conveys fluid laterally from the pressurized pipe through the web in one of the at least two vertical posts to another planter shelf being arranged between said one of the at least two vertical posts and an additional third vertical post; and wherein the fluid dispensed is configured to irrigate, from above or below, at least one seed/plant root retaining matrix that is configured to be coupled to at least one of: a bottom wall flange defining the fluid irrigation reservoir and the full height side wall of a planter shelf; and the weight of at least two planter shelves alone, or in combination with at least one base panel, wall panel or header panel is configured to be directed to a below retaining surface substantially without applying vertical loads on the at least two posts. each post is elongated, vertically anchored to at least one retaining surface and comprises at least one web and at least two flanges; each planter shelf is elongated and comprises: a top wall flange, a bottom wall flange, a full height side wall connecting the top wall flange and the bottom wall flange, a short side wall and two endcaps walls; the opposing ends of a first horizontally oriented planter shelf are disposed between the at least two flanges of each of the two vertical posts; the opposing ends of a second horizontally oriented planter shelf are disposed between the at least two flanges of each of the two vertical posts retaining the first planter shelf, and wherein the at least two planter shelves are configured to slide downwardly into a position in which the bottom wall flange of the second planter shelf couples with the top wall flange of the first planter shelf by at least one reciprocating mechanical key; the endcaps' walls coupled to a top surface of the bottom wall flange at both ends of the first and second planter shelves and to their side walls define a fluid irrigation reservoir that is open to the above; and in which system piped fluid is configured to directly flow to a fluid irrigation reservoir of a planter shelf through an opening in the web of one of the vertical posts and exit the fluid irrigation reservoir through at least one opening (24, 39) in a bottom wall of the fluid irrigation reservoir; or piped fluid is configured to indirectly flow to a fluid irrigation reservoir of a planter shelf via a pressurized pipe extending between coupler pipes in the webs of the at least two posts, said pressurized pipe having at least one emitter nozzle and being disposed at the bottom of the fluid reservoir of the planter shelf, wherein one coupler pipe delivers fluid to the pressurized pipe while the other coupler pipe conveys fluid laterally from the pressurized pipe through the web in one of the at least two vertical posts to another planter shelf being arranged between said one of the at least two vertical posts and an additional third vertical post; and wherein the fluid dispensed is configured to irrigate, from above or below, at least one seed/plant root retaining matrix that is configured to be coupled to at least one of: a bottom wall flange defining the fluid irrigation reservoir and the full height side wall of a planter shelf; and the weight of at least two planter shelves alone, or in combination with at least one base panel, wall panel or header panel is configured to be directed to a below retaining surface substantially without applying vertical loads on the at least two posts.