I recently red in a book dedicated to wild tulips that if it is today generally admitted that blooming period mostly depends on temperature and height criteria, the blooming schedule of the miscellaneous species is known as invariable.
In spite of the above, I noticed this year again how careful we must be facing such statements.
In fact, when I was growing tulips on Creteil roofs (Paris Crown) first blooming were Tulipa schrenkii & Tulipa polychroma. Now, since tulips are growing in a garden, things become different.
Last year, Tulipa hissarica was two weeks earler than any other tulip of the collection. This year, we are far from this. The earliest tulip is without any doubt Tulipa kaufmanniana type or under its variant ‘Early Harvest’.