American Airlines said this is the busiest time of year for flower shipments.
"Probably in the last week or so, we got about 10,000 pounds of flowers," said American spokesperson Tim Smith.
That equals up to a thousand boxes a day.
Since most of the flowers come from overseas, they must be inspected by U.S. Customs agents.
"The main thing we're looking for are insects that are not already established in the United States," said Customs spokesperson Morris Bigham.
Because flowers are perishable, speed is critical. American said most flowers are shipped using its Expedite FS express service, which guarantees that shipments will arrive on a specific flight.
Some florists are so anxious to receive their shipments, they're waiting at the airport when the plane arrives. Most flowers have left the airport within three to six hours of their arrival.