Leaves contaminate the vase water, just like stems do. The stem has to be in water; the leaf, however serves no purpose in the water, in fact, it has a negative impact. Therefore, it is recommended to remove the leaves right up to the water level. Leaves take much longer to become limp and there is less stress on the flower, which already has to put out enough effort to keep its equilibrium.
Flowers are grown, shipped and sold over the world. The flower stems as well as leaves carry micro-flora with them all the way to the customer’s vase. The conditions before harvest also influence the flower development in the vase.