How many months do you have to grow your hair to put it in a ponytail?

Depends on the size you want the pony tail and the size of your head. I know my hair is the same length as another girl's, yet her ponytail is at least three cent longer than mine. Although i have a much bigger head than her lol

It should take about six months if your starting from a completely bald head if you want a very small (very) ponytail