A cut flower pulls water into its stem through the phenomenon of capillary action. When a cut flower stem is placed in a vase, the water adheres to the stem walls and creates an upward force that is stronger than the force of gravity.
As water travels up a cut flower stem, its cohesion and surface tension keep the molecules from scattering. As a result, the surface stays intact as the water moves. With adhesion and cohesion, the water molecules stick to each other and the sides of the plant stem, allowing them to travel throughout the plant. The water continues until it reaches the tips of the plant or the force of gravity becomes too strong.