Cattleya orchid plant in bloom
image by Javier Martin:commons.wikimedia.org
The two most important aspects of handling cattleya orchids as cut flowers are keeping the stem healthy enough to draw water and controlling the development of bacteria in the vase water. When these two primary requirements are met, cattleya orchids can survive more than a week after being cut from their plant.
Prepare a clean vase or watertight container of your choice with fresh, cool-to-tepid water. Fill no more than the mid-point, as the orchid stem can only drink from the area at or near the cut. The higher the waterline in the vase, the greater the chance of water touching the foliage and bacteria developing.
Mix a commercial or homemade flower preservative into the vase water to kill bacteria and provide nutrition for the cattleya. Dissolve the commercial product in the water according to its label directions. To make your own preservative, simply add one teaspoon of granulated sugar and two drops of household chlorine bleach to the vase water and swish around to combine.
Fill the sink or a deep bowl with cool water. Place the cattleya stem in the water and make a fresh 45-degree angle cut across the stem while still submerged. This will ensure that air does not get trapped in the stem, and water is drawn up instead. Cut the cattleya stem to the proper length for your container and arrangement design but not more than absolutely necessary. This will leave you enough stem to make fresh cuts every few days while the bloom is alive. Immediately place the cut cattleya bloom in the prepared vase water and proceed to your next cut, repeating the process.
Set your cattleya cut flower arrangement in a cool, shady location out of direct light. Every two to three days, discard the vase water and rinse the vase, refilling it with tepid water and more floral preservative. Re-cut the cattleya stems by at least one-fourth of an inch while submerged under water and place back in the vase. Return the vase to its cool shady location.