Orchid flowers are not commonly stored. They can be held for short and long terms under optimum conditions, however. Most orchids are of tropical origin, so they should be stored in similar environment. Longer storage results in chilling injury which can show up in 24 hours as blackening or browning of flower parts. These flowers can last 6 to 7 weeks on the plant.
Many floral operations have a separate cooler for orchids and tropicals.
Some orchids may be stored dry-pack, but generally they should have their stems in vials of water. Preservative may be used in the water tubes, but there is not consistent evidence showing that it extends vase life, but mainly helps by keeping water in tubes clean. Make sure all tubes are full prior to storage. Some orchid species are very sensitive to ethylene, so particular precautions should be taken to ensure adequate ventilation and sanitary conditions are used. Avoid storing in tightly closed plastic bags.