That's the question asked by the young son of a walk-in customer recently. The gentleman smiled and said, "About 5 days."
THIS was a very astute customer!
But it occurred to me that he might not know WHY "Supermarket Flowers" do not last as long as "Florist Flowers." After all, they all come from pretty much the same place.
The primary difference, I believe, is in what happens AFTER the Supermarket receives the flowers. In pretty much every supermarket that I have seen, their flowers are displayed in open air coolers. Most florists keep their ready-to-sell flowers in enclosed coolers.
This seems like a pretty minor detail. But is it?
In an open air cooler, only the stem ends are cooled. The blooms and foliage are in a brightly lit environmentand and are at at ROOM TEMPERATURE.
It is a well known fact that bright light stimulates flowers to bloom. And, if the blooms and foliage are at room temperature, they will start to "age" as soon as they are put on display.
There may be other factors. One MIGHT be that florists are trained in floral preparation. That means that they are more likely to know the proper steps that are needed in order to properly prepare cut flowers for display.