So, your plant is not cooperating, and it is blooming NOW instead of the day of the flower show. No problem!! You can preserve a flower up to a week in advance. Select a freshly opened flower. Take a #4 coffee filter, cut off the bottom. Mark the name of the bloom on the filter. Place the flower through the hole in the bottom. Wet a cotton pad or cotton ball, paper towel, etc and place on the end of the stem. Secure the moistened pad with aluminum foil. Spray the filter lightly with water to moisten it, then put the bloom in an airtight container and place in the middle of your refrigerator. Make sure to avoid any extra-cold spot where it might freeze.
On the day of the show, your bloom will be fresh as new!