That is an excellent question! Ecologists have
been trying to answer this question for centuries.
Flower blooming is often related to a number of
different factors including genetics, water
availability, sunlight, temperature and even
herbivory by animals!
Flower creation is tied to various chemical
signals that pass through the plant that determine
when a plant will bloom. Sometimes reducing
water will make a flower bloom faster. Other times
flowers bloom based on the hours of sunlight it
receives each day. Here is a more thorough answer
to your question :)
see here to learn more