In this economy, cut flowers really are a luxury, so you must take every step to ensure the longest lasting flowers once they hit your vase. Most people are familiar with the recommendation to re-cut your flowers before you put them into the vase, to ensure maximum water uptake. However, there is a further step you can take to enhance this water uptake: hardening.
The process of hardening simply refers to playing with temperature to get the most water into the stems, and to get the least amount of water to leave the flowers. To do that, place your freshly cut stems into very warm water, approximately 110 degrees. Not sure what 110 degrees feels like? It’s just a few degrees warmer than the hot tub you use at the gym.
Placing freshly re-cut flowers in water of this temperature ensures that the water molecules are moving rapidly up the stems. This optimal temperature not only gets water moving up the stems, but it’s mild enough to avoid scalding your flowers.
The second part of hardening involves keeping your flowers cool. As soon as you plunge the bouquet into the very warm water, you should move the flowers into a cool place, preferably a refrigerator. While your stems are busy taking up warm water, the cool ambient temperature will prevent water loss and respiration from occurring in the flowers. When the water has cooled completely, the hardening process is finished, and your fully hydrated cut flowers are ready to display.