Keep the vase filled or floral foam soaked with water containing a flower food provided by your florist.
If the flower food solution becomes cloudy, replace it entirely. If possible, recut stems by removing one to two inches with a sharp knife.
Keep flowers in a cool spot (65 to 72 degrees Fahrenheit), away from direct sunlight, heating or cooling vents, directly under ceiling fans, or on top of televisions or radiators. (Appliances like televisions give off heat, causing flowers to dehydrate.)
If you can't get your flowers in a flower food solution right away, keep them in a cool place.
Fill a clean, deep vase with water and add the flower food obtained from your florist. Be sure to follow the directions on the package.
Remove leaves that will be below the waterline. Leaves in water will promote bacterial growth.
Recut stems with a sharp knife. Do this underwater -- this allows the stems to draw in water instead of air -- and place the flowers in the vase solution you've prepared.
When selecting flowers, look for flowers with upright, firm petals and buds beginning to open. Yellow, spotted or drooping leaves are signs of age.
When using woody stems and branches (such as quince, forsythia or lilac), cut the stem with sharp pruning shears. Place in warm water containing fresh flower food to promote flower opening.
You can store your prom/dance flowers in the refrigerator overnight. Place them near the front of the refrigerator so there is no chance they will freeze. Never place them in the freezer!