The purpose of this study was to evaluate the efficacy of eggshells and fruit peels as organic amendments to promote maize plant growth in both greenhouse and field settings. Eggshell powder increased the seedling emergence rate by about 10–20% over the control treatment in the greenhouse experiment. The combination of eggshells and fruit peels had the greatest impact on vegetative growth parameters in the field study, boosting vegetative growth by about 35.6%, leaf area by 14.4%, and fresh biomass by 76.6%. The addition of eggshells and fruit peels improved soil chemical characteristics, especially soil nutrient availability, including phosphorus, potassium, calcium, and organic matter. This result is particularly relevant for sandy soils, which have low nutrient retention capabilities. Therefore, the experiment showed that eggshells and fruit peels can serve as efficient and eco-friendly soil amendments that enhance seedling emergence, vegetative growth, and soil fertility.