Chill and heat requirements: from dormancy to flowering

Cherry trees originated in the cold climates of Europe and western Asia. As an adaptation to very cold winters, cherry trees enter a period of dormancy designed to protect cold-sensitive tissues such as shoots and flowers from freezing injury (Darbyshire, 2016). Successful release from dormancy requires a specific minimum cold temperature requirement be met for growth to resume when temperatures warm in spring. This cold temperature requirement is cultivar specific and referred to as the “chilling requirement”.