FAIL:- Once The Ground has Started cooling the bulbs are ready to be planted.
WINTER:- Tulips needs 13-15 weeks of cool weather to help establish roots and before the shoot will emerge.
SUMMER:- After blooming the leaves dry out sending the nutrients to the bulb.
During dormancy, the flower forms in the bulb by late summer.
SPRING:- After cooling and once the sun starts warming the ground the tulips know it is time to bloom.