Earlier flowering is one of the most widespread biological responses to climate change, and these shifts in the timing of flowering are especially pronounced at high elevations and high latitudes, places where climate change is occurring rapidly. We will take a virtual trip to the Colorado Rocky Mountains to examine why plants are flowering earlier. What is driving these changes in flowering dates? And then we will examine some of the ecological consequences of earlier flowering in the lab. In particular, we will think about the consequences of earlier flowering for plant populations and for interactions between plant species for pollination.