The theory: Contains a biocide to kill bacteria, an acidifier to help stems drink water, and a sugar to nourish the blooms.
Day 1: One tablespoon from a packet is mixed into the water.
Day 4: Has sucked up more water than any other bouquet. Opening so beautifully that another tablespoon of the flower food isn't added until Day 5.
Day 7: The full bouquet has a soft, dramatic droop and, though fading fast, still gets Best in Show. (See photo, left.)
The verdict: The winner of the bunch. (Flower food is available at florist shops.)