To germinate yellow heart watermelon seeds, soak them in warm water for 12–24 hours to soften the outer coat. Plant in well-draining soil, ½ inch deep, in a sunny spot with 6–8 hours of daily light. Keep soil moist but not soggy, and maintain a temperature of 75–85°F (24–29°C) for optimal growth. Germination takes 7–10 days, and seedlings thrive in warm, frost-free conditions. These seeds grow into productive vines that yield juicy, sweet yellow-heart watermelons—ideal for summer snacks, salads, or sharing with family and friends.