Excavated soil containing non expansive clays can be used to develop low-carbon 3D-printable materials. To further enhance the moisture sensitivity and other physical properties, geopolymer containing blast furnace slag (GGBS) and fly ash (FA) can be an excellent stabilizer. However, due to rapid hydration in GGBS-rich geopolymers, the open printing time is too short to construct large-scale 3D-printed elements. This research explores the addition of sucrose to introduce controlled retardation in 3D-printable geopolymer-earth materials (GP-E). By adding sucrose at 1.0% by weight of the binders (GGBS + FA), the open printing time of GP-E can be prolonged by 4–5 times compared to that of control (no sucrose). The longer open printing time is attributed to slower hydration kinetics leading to longer flow retentions and a controlled development of plastic viscosity and yield stress. Deprotonation of sucrose in alkali (NaOH in this case) increases the negative charge and form complexes with metal ions (Na+, Ca2+), leading to better dispersion and particle repulsion in the fresh stage. The filling effect of clay and its dissolution to form zeolitic products synergistically balances the repulsive forces due to sucrose, leading to superior shape stability and 5 times higher buildability during printing. In summary, the research demonstrates a strong potential of sucrose as a bio-based set controller for printing large-scale 3D-printable geopolymer stabilized earth structures.