Cut flowers will die eventually, but they don't have to wilt right away. Whether you cut the flowers yourself or receive an arrangement from a flower shop, there are steps you can take to prolong their lives for up to two weeks. While each specific type of bloom may require slightly different care, tulips, for example, continue growing after being cut, adding up to several inches to their stem length in a vase.
Scrub, clean and thoroughly rinse a flower vase before using it.
Fill the flower vase halfway with room-temperature water and add a floral preservative. If you don't want to use a commercial product, add 2 tbsp. of fresh lemon juice, 1 tbsp. sugar and 1/2 tsp. bleach to each quart of water in the vase as a homemade floral preservative. While you're at it, fill a sink several inches deep with room-temperature water.
Hold the cut flowers up against the base of the vase and eyeball roughly where the water line will fall on the stems once the vase is filled to within an inch of the brim. Don't forget to figure in that you'll be cutting about an inch off the bottom of the stems before putting the flowers in the water. Next, pull or cut off any leaves that fall beneath the estimated water line, but leave any thorns in place.
Hold the ends of the flower stems in the sink, under the water, as you trim the ends off the flower stems at a slant, using a sharp knife that does not have a serrated blade. Place each stem in the vase right after you cut it.
Keep your cut flowers away from fruit and out of direct sunlight, warm drafts and direct heat. This includes not placing them on top of the refrigerator or television set. Shift your flowers to a cool place at night to keep them fresher.
Pour the old water out of the vase every two days and replace it with fresh, room-temperature water. Add more floral preservative. Check on the flowers each day and remove any that show signs of rot.