Cut garden flowers in the morning before it gets warm. This way the flower has taken in plenty of moisture and isn't in a dehydrated state when you cut it. Selecting young flowers, in bud form or recently open, also helps assure a longer cut flower life. Full-blown blossoms tend to wilt sooner and lose petals once cut.
Cut the flower stems at a 45-degree angle to expose a wide area of stem to water. Clip off all the lower leaves so none will be below the waterline to decay.
Fill the vase to within two inches from the top. Add the floral food. Use 1 tsp. of floral food per quart of water or defer to the package instructions.
Change the water and add floral food at least every other day.