Hydrating is the process by which water and other ingredients are rapidly introduced into flowers to make them turgid.

Stem anatomy: Xylem, phloem, vascular bundle, vessel, tracheid, pith, sieve plate, pit and stele are some of the terms which describe the food and water conducting systems of plants. For the purpose of this manual, only the xylem will be discussed.

Xylem is the principal upward and horizontal water conducting tissue in plants. Made up mainly of tracheids and vessels, these cells are dead at maturity. Individual cells of various lengths are connected end-to-end to form continuous pipelines throughout the plant.

In simplistic terms, xylem can be viewed as thousands of tiny straws connected end-to-end. In general, the length of these straws is a few inches or less. Filters or valves are located at the points where the straws connect. These filters or valves can influence what passes from one straw to the next. Specifically, microorganisms, debris and air bubbles are restricted from moving through these filters or valves.

Role of dirt, debris, microbes and air bubbles (embolisms): In healthy cut flower species prior to harvest, the plant root system provides clean water to the xylem tissue. Once flowers are harvested, inhibitors of water movement in xylem can reduce the flower life.

Air bubbles can form immediately upon cutting. They also form later, as the flower loses water when being held dry. Dirt, debris and microbes can enter xylem tissue at any point in the marketing channel, simply from normal handling.