To put it simply, Frost flowers are flowers made of frost. More accurately, frost flowers are nothing like that, so let’s put it technically instead: they’re buildups of ice particles around the base of certain plants and types of wood. When the temperature outside the plant is below freezing and the temperature within them is not, then water is pulled to the surface in a process similar to transpiration. This leads to a fragile chain of ice being pushed outward, which ends up forming sprawling, delicate formations. So they’re not exactly flowers—more like leaves, if anything—but they’re just as pretty to look at, and at least twice as cool.