Put on latex disposable gloves prior to beginning the cutting or searing process. Although the sap of poinsettias is not toxic, it can cause mild skin irritation in some individuals.
Place a pillar candle near your work area and light the wick with a match to prepare for the searing process.
Grasp one of the poinsettia blooms and trace the stem downward to the base of the plant. Cut the stem off using a straight cut and hand pruners.
Look at the length of the stem and determine if you want to cut it further, depending on the project you are using it for. If desired, cut the length of the stem shorter with the hand pruners.
Blot the end of the stem on a paper towel to absorb some of the milky sap.
Grasp the stem at least 3 to 4 inches from the bottom and hold the cut end of the stem over the top of the candle flame. Hold the stem in the flame for approximately five seconds.
Fill a vase with lukewarm water, and add floral preservative powder. Insert the bottom of the poinsettia stem into the water as quickly as possible. Wait one hour and examine the poinsettia. If searing was successful, the stem will still be fully rigid. If the flower appears wilted, cut 1 inch off the stem and repeat the process.