Cut the red ginger flower when it is ½ to 2/3 open, but before it completely opens. Cut through the stem with a sharp knife at the base where the stem emerges from the main plant.
Place the cut stem in a bucket of warm tap water. Immediately placing the stem in water prevents air bubbles from entering the stem, which extends the life of the flower.
Dissolve a packet of cut flower preservative in a vase filled with 120 degree Fahrenheit tap water.
Strip the leaves from the ginger stem, leaving only the top one-to-three leaves in place. Cut the bottom of the stem at a 45-degree angle using a clean knife.
Transfer the prepared ginger flower to the vase. Place the vase in a cool room with receives bright but indirect sunlight.
Replace the water in the vase with fresh water and preservative every two to three days. Replace the water more frequently if it becomes cloudy or discolored.