As a cut flower, tulips have the distinctive characteristic of continuing to grow in the vase and stretch toward a dominant source of light. This trait can cause a carefully arranged floral bouquet to disassemble itself into something quite different as the stems may extend by as much as 2 inches, causing the blossom heads to droop. The flowers also open wide in bright light, sometimes exaggerating the drooping effect, although they usually close again at night if the room temperature is moderate to cool.
There are a number of ways to ensure that tulip blossoms hold in a cut bouquet for seven to 10 days. When you first get the bouquet home, lay it out on newspaper and, one by one, cut 1/2-inch diagonally from each stem. Do this under cold running water to ensure that air does not form a bubble in the freshly cut stem. Wrap the newspaper in a cone shape around the newly cut flowers and place them in cool water in a clean container for an hour or two, making sure the newspaper is above the water level. Cut an additional 1/4-inch from each stem before the flowers arranging in the display vase.
Use a vase that will hold the blooms upright. Generally, the height of the flowers in the vase should be about one and one-half times the height of the vase. Prepare a solution of florist preservative and water, following the instructions on the package. Many other additives are favored folk remedies, such as bleach, sugar, a penny, lemon soda or mouthwash, but none of these is as effective as florist preservative.
Before arranging the bouquet, use a sharp knife to make a tiny slit in the stem just below the head of each flower. Alternatively, run a sharp needle through the stem from one side to the other, just below the head of each flower. These simple techniques will curtail continued growth, and the blossom heads will remain close to their original placement. If you enjoy watching your tulips rearrange themselves in the vase as they grow, omit this step before arranging the flowers in the vase.
Place the vase away from extra heat and light from windows, heating vents or drafts. A cool, shaded place is best for tulips to maximize their life span in the vase. Top off the water in the vase each day as these flowers are especially thirsty. If you notice any cloudiness in the water, change it completely and add more florist preservative.