There are various synonyms for the phrase "springing up." Some of these synonyms include emerging, appearing, popping up, sprouting, blossoming, developing, growing, materializing, and manifesting. Each of these synonyms can be used in different contexts to convey the same meaning of something new or unexpected suddenly coming into existence. For instance, "a new flower emerged in the garden," "a new shop suddenly popped up in the neighborhood," or "a new idea sprouted in his mind." These synonyms can be used interchangeably to create variety and depth in written or spoken communication.