There are many factors that contribute to when tulips bloom, like the weather, how much sun they get, how deep they are planted and what type of tulips they are.
There are actually thousands of different types of tulips, and they are broken down into 15 specific classifications. I am focusing on 3 basic variations for this post: early, middle, and late.
Early tulips generally bloom in late March to early April. They tend to be about 8 to 15 inches in height. Early tulips begin blooming while daffodils and crocus are still in bloom.
Middle tulips bloom 5 to 10 days after the early tulips and tend to be a little taller than the early ones, and a little hardier and more suited to cutting and bringing inside to enjoy.
Late tulips are truly elegant, they tend to have long sturdy stems and large blooms and include the parrot varieties. Many tulip festival patrons miss out on these beauties because they bloom so much later- 5 to 10 days more after the middle tulips, often blooming well into June and the crowds at the gardens tend to dramatically taper after the advertised days of the Tulip Festival have passed. The tulips are still there, just not the venders live music and such.
I hope this information is helpful in getting the most enjoyment out of tulip season this year, I still think a membership to the gardens is a great way to go and then go a few times so you get to see more varieties of tulips.