This study investigates the potential use of pulverized water hyacinth (PWH) as a concrete admixture and water hyacinth extract (WHE) as a natural superplasticizer to develop a more economical and environmentally sustainable concrete mix. PWH, derived from dried and pulverized water hyacinth, is explored for its potential to reduce material costs and promote the reuse of green waste; however, its high water absorption is known to reduce concrete workability. To address this limitation, WHE was incorporated as a workability-enhancing agent to counteract the adverse effects of PWH. The study focused on optimizing the proportions of PWH and WHE to achieve acceptable workability and compressive strength without compromising structural performance. Slump and compressive strength tests were conducted to evaluate the fresh and hardened properties of the proposed mixes. Results indicate that increasing PWH content reduced slump but did not adversely affect compressive strength at low dosages, while WHE consistently improved workability but caused significant reductions in compressive strength. Optimization analysis identified an optimal mixture of approximately 0.48% PWH with no WHE, yielding a predicted compressive strength of 26.75 MPa. The findings demonstrate that PWH can function as an effective bio-based micro-admixture in concrete, whereas WHE acts primarily as a workability modifier whose dosage must be strictly limited, underscoring the importance of dosage optimization in sustainable bio-admixture applications.