How long will a bouquet of flowers last without water?

You would definitely need to put them in water. Flowers are ok out of water for a short period of time, also depends on what flowers you use. Some are heartier like Carnations and Daisies, but leaving flowers out of water even for a few hours puts a stress on the flower. You can have water pics put on the stems, but the flowers usually drink the water in the pics within a few hours. Your best bet is to purchase flowers that are designed in a vase. Always keep all flowers out of sunlight. Also, please support your local florist. The quality and design is so much better than grocery stores, plus you will be supporting a local, small business. In a tough economy, supporting local, small business is best.