The fabricating of extremely effective, economical, ecologically safe, and reusable nanoparticle (NP) catalysts for the removal of water pollution is urgently needed. This study, spectroscopically optimizes the process parameters for the biogenic synthesis of AgNP catalysts using Cledrdendrum infortunatum leaf extract. The optimization of several synthesis parameters was systematically studied using UV-Vis spectroscopy to identify the ideal conditions for AgNPs formation. The AgNPs are spherical with a size of ~ 20 nm, pure and stable. Mechanistic insights into the biogenic synthesis process were explored. The photocatalytic performance of biogenic AgNPs was evaluated for the degradation of three common (crystal violet, thioflavin T, and methylene blue) dyes as models in ternary mixtures under the influence of sunlight. AgNPs show excellent photocatalytic efficiency in terms of degradation percentage (82.89-96.96% within 110 min), kinetics (0.0247-0.0331 min), half-life (20.96-28.11 min), and T (48.67-65.28 min) and also easily recovered and reused. Ecological safety assessment of the treated wastewater was assessed on the growths of rice, mustard, and lentil plants, and preliminary findings demonstrated that seedling growths for treated wastewater were nearly similar to the control sample but retarded in dye-contaminated wastewater suggesting potential use of treated wastewater for sustainable agriculture without compromising ecological balance. So, this study explores biogenic AgNPs as cost-effective, safe, and sustainable photocatalytic agents for the remediation of hazardous mix dyes and real-life applications of treated water for agricultural purposes.