Why do flowers wilt in the vase?
When flowers in a vase drop their heads after a short time, it is usually due to a lack of water. Although they are in water, the greatest danger for cut flowers is that they die of thirst. This is because their pipes become blocked and they can no longer reach the water.
Like all plants, flowers constantly release water into the surrounding air through their leaves. This evaporation creates a suction effect that draws new water up the stem.
Cut flowers are cut off from their natural supply. Instead of the root system, only a small cross-section of the stem is available for water absorption.
The pipes are also clogged with bacteria. To keep micro-organisms at bay, it is advisable to clean vases thoroughly, leave no leaves in the water and change the water every two to three days. The stems can be re-cut at the same intervals. It is best to do this with a sharp knife and at an angle, otherwise soft stems such as those of a gerbera will be bruised and unnecessarily injured - providing bacteria with new points of attack.
Flowers such as roses that are still to bloom draw on their energy reserves. Indoors, they lack the sunlight they need to produce their own sugar. Adding sugar to the flower water therefore feeds the bacteria at the same time. In addition to sugar, flower fresheners also contain bacteria-inhibiting substances. This means that the birthday bouquet will last a few days longer.
Temperatures above 20 degrees, dry heating air and little light accelerate the ageing process. Placing bouquets in a cool hallway or cellar at night, for example, has the effect of refreshing the flowers. Even a day-night change like this can significantly extend the shelf life. The location in the room should also be chosen carefully, as cut flowers cannot tolerate direct radiant heat from radiators and too much water is lost through the leaves. It is therefore better to place them near a window, away from radiator heat and draughts. A bowl of fruit near the bouquet may look attractive, but often has fatal consequences for the flowers. This is because ripening fruit releases ethylene, a stress and ageing hormone. Cut flowers react to this gas by shedding buds and flowers, leaves turn yellow and wilt. It is therefore better to place bouquets of flowers and bowls of fruit in different rooms.