Ask Everything How Long Can a Flower Live After It's Picked?
Short answer: months if you're very careful.
Most cut flowers normally last a week or two, but their "vase life" varies greatly. Genetics of course plays an important role, but so does how the plant is grown and harvested.
The best thing you can do to make a flower last really long is to put it in a temperature very close to freezing.
At the time of cutting, the stem will have a source of starch and sugar inside - if the plant was grown in good light and harvested in the afternoon. This supply is fuel, and once depleted the flower can take up nutrients from the water in a vase. That's why people often give "flower food" to their bouquets.
However, the ability of cut flowers to absorb water and nutrients deteriorates over time. These processes are usually limited to blockages in the trunk caused by air bubbles or bacterial growth. Adding a little bleach to the water can prolong the life of the flower by removing microorganisms, and mild acid tends to facilitate circulation. Temperature also makes a big difference: "The best thing you can do to make a flower last really long is to put it at a temperature very close to freezing," says John Dole, professor of flora culture at North Carolina State University. As long as you don't freeze the flower's sap, which is certainly a fatal mistake, cold will slow down aging.
Even under ideal conditions, a plant's genetics play an important role in the longevity of its flowers. Daylilies, for example, last no more than a day. Other species have surprising endurance. "We're working here with a flower called pineapple lily, and it takes seven weeks in one of the treatments," says Dole. “When they're gone this long, it falls into the 'please die now' category. . . I want to do this experiment!”
