If roses have survived on Earth for more than 35 million years, why can't they last more than a few days in a vase? Fortunately, there are some tricks for preserving a bouquet of roses. Begin by trimming excess foliage from the bottom of the stem. If you like, remove the flowers' thorns, but keep in mind that it may shorten their vase life. Use a rose dethorner, or wearing leather work gloves, slide your hands along the stem from top to bottom to remove thorns.
Flowers last longer if their stems are cut under water. Use a sharp knife, and cut the stem on a slant so it can absorb as much water as possible. Next, place the roses in a flask filled with 2 inches of warm water (no hotter than 110 degrees); this expedites the flow of water into the flower. Add either cut-flower food or a teaspoon of sugar and a couple drops of liquid bleach to a vase filled with cool water up to the point where the foliage will hit. After 5 minutes, transfer roses to the vase.
To revive wilted flowers, submerge them overnight in a sink filled with cool water. Tie them together with cord, and attach fishing weights or washers as an anchor.