Here are some Flower Care Tips from Aboutflowers.com

Aboutflowers.com is a website hosted by Teleflora with a wealth of information for the flower loving consumer.

Most floral arrangements last 4-7 days or longer, depending on the flowers used and the care they receive. The Society of American Florists provides these tips for longer-lasting, more vibrant flowers:

For floral arrangements

• Keep the vase filled (or floral foam soaked) with water containing a flower food provided by your florist. Flower foods make flowers last longer but it is important to follow the mixing directions on the flower food packet. Most packets are to be mixed with either a pint or a quart of water. Flower foods should not be diluted with more water than is specified on the packet.
• If the flower food solution becomes cloudy, replace it entirely with properly mixed flower food solution. If possible, re-cut stems by removing one to two inches with a sharp knife. Be sure to use a sharp knife or clippers that will not crush the stems. Immediately place the stems into solution.
• Keep flowers in a cool spot (65 to 72 degrees Fahrenheit), away from direct sunlight, heating or cooling vents, directly under ceiling fans, or on top of televisions or radiators. (Appliances like televisions give off heat, which causes flowers to dehydrate.) Most flowers will last longer under cool conditions.