A modular composting garden container system, comprising: a base sized, shaped, and positioned to receive, store, and provide access to nutrient-rich drainage from the soil or the compost material or both; a plurality of stackable rings sized and shaped to be removably assembled into a tower of selectable height and mounted above the base, the plurality of stackable rings each comprising a cylindrical body having a bottom, open top, and one or more sidewalls extending from said bottom to said top, said one or more sidewalls defining a plurality of circumferential, outwardly-extending protrusions along a top edge of said one or more sidewalls, the tower comprising a first interior sized, shaped, and positioned to hold soil introduced from a top of the tower, and a first exterior surface defining first apertures between successively stacked ones of said stackable rings, the first apertures sized, shaped, and positioned to facilitate the growth of plants there through from the first interior, said first apertures having outer edges defined by said outwardly-extending protrusions; a plurality of stackable tube sections sized and shaped to be removably assembled into a compost tube assembly of selectable height and mounted within the first interior of the tower and above the base, the compost tube assembly comprising a second interior sized, shaped, and positioned to hold compost material introduced from a top of the compost tube assembly, and a second exterior surface defining second apertures therein sized, shaped, and positioned to facilitate the passage of worms there-through from the second interior; and a plurality of holding struts sized, shaped, and positioned to removably connect the compost tube assembly with the tower and to securely locate the compost tube assembly relative to the tower. a base sized, shaped, and positioned to receive, store, and provide access to nutrient-rich drainage from the soil or the compost material or both; a plurality of stackable rings sized and shaped to be removably assembled into a tower of selectable height and mounted above the base, the plurality of stackable rings each comprising a cylindrical body having a bottom, open top, and one or more sidewalls extending from said bottom to said top, said one or more sidewalls defining a plurality of circumferential, outwardly-extending protrusions along a top edge of said one or more sidewalls, the tower comprising a first interior sized, shaped, and positioned to hold soil introduced from a top of the tower, and a first exterior surface defining first apertures between successively stacked ones of said stackable rings, the first apertures sized, shaped, and positioned to facilitate the growth of plants there through from the first interior, said first apertures having outer edges defined by said outwardly-extending protrusions; a plurality of stackable tube sections sized and shaped to be removably assembled into a compost tube assembly of selectable height and mounted within the first interior of the tower and above the base, the compost tube assembly comprising a second interior sized, shaped, and positioned to hold compost material introduced from a top of the compost tube assembly, and a second exterior surface defining second apertures therein sized, shaped, and positioned to facilitate the passage of worms there-through from the second interior; and a plurality of holding struts sized, shaped, and positioned to removably connect the compost tube assembly with the tower and to securely locate the compost tube assembly relative to the tower.