You will know that Plumeria seeds have germinated when you see the emergence of the primary root (radicle) and the first leaves (cotyledon). The radicle is the first structure to emerge from the seed coat, followed by the cotyledon, which may appear as a small, green structure. Once you observe these signs, it indicates that germination has occurred successfully. Seed germination can vary in speed, and some seeds may germinate earlier or later than others. Continue to care for the germinated seeds as they develop into seedlings and establish their root systems.