The process of a seed sprouting is called germination. In biology class, you might conduct an experiment to see which factors affect the germination of radish seeds.
Inside every seed is a tiny baby plant that stays there, protected by the seed's coat, until it's ready for germination. Germination can start when moisture penetrates the seed and the air and soil temperature is high enough for the plant to grow. You can also use this word for a figurative type of sprouting: "That class was perfect for the germination of new ideas." The word germination comes from the Latin germinationem, "a sprouting forth or budding."