Scientists have known since the 1930s that plants sense the length of the days and, somehow, use that information to decide when to flower. Russian scientists back then speculated that a mysterious substance must be transported from leaves to shoot tips, stimulating the formation of flower buds. They called the mystery chemical “florigen.” In 2005, a trio of new studies revealed how it works, including why flowers spring forth in certain spots on a plant. The findings were... [read more]