The work investigates causes of unsatisfactory seed yields in sweet clover through two linked studies. The first reports controlled pollination experiments that assess self- versus cross-pollination, insect exclusion and visitation, floral structure and pollen germination, and environmental factors such as moisture and weather on pod set and shedding. The second analyzes seed-coat anatomy and chemistry, comparing permeable and impermeable seeds, testing treatments that alter coat permeability, and relating coat structure to water absorption and germination. Methods, observations, and practical implications for improving seed production are presented.