2 -- 3 month, 55 inches
Some flowers take only a few days to grow, while others may take weeks, months even, to grow.
It depends on the type of environment it is in. If it is in an healthy environment it can last for weeks and months or if it is in an unhealthy environment it can last for 5-6 days.
If you are pressing flowers in a book, it will take between 7 and 10 days. I always give them at least ten just to be sure though
it takes about two weeks or so for a flower to change from the bud stage to the flower stage.