The suction of transpirational pull places water under tension in the xylem of an actively transpiring plant. Thus, when stems are cut, air is drawn into the exposed vessels and blocks the flow of water. In the garden, flower stems should always be cut longer than desired and recut to the correct length while holding the stems under water. If the stems are then quickly transferred to a vase, the transpiration stream continues uninterrupted, without the blossoms wilting. Scissor-type pruning shears or a sharp knife should be used to make clean cuts so the ends of the xylem vessels remain open.
