After warm-water placement, wrap the flowers with paper or plastic to prevent rapid air movement over them, reducing water loss. Use only fresh oasis or floral foam. Previously used material most likely will be bacteria-contaminated. Water high in fluorides or salts hastens cut flowers' death, so use filtered or distilled water if necessary. Add a flower preservative to the water.
Preservatives promote water and nutrient uptake and inhibit bacteria and fungi.
When the solution clouds, indicating the presence of microorganisms, freshen it. Unfortunately, many home remedies such as aspirin or copper pennies in the vase water don't prolong cut flowers' lives. However, you can substitute a light-colored soft drink for a preservative, although you should not use a diet drink. Don't place flowers in direct sunlight or on a TV set. Flower aging is more rapid in high temperatures.