Preserving the cut flowers that many people will receive on Valentine's Day is easy but beware of urban legends. Aspirins, sugar packets, copper pennies, a finger of Coca-Cola, can all be described as tricks to preserve cut flowers longer; however, it is good to know that there is little truth to them.

FloraHolland, the Dutch growers' cooperative founded in 1863 and specialising in sales of plants and cut flowers, wanted to see it through in 2009 and sponsored a study, to test all these imaginative remedies. Recreating the home environment, various solutions were tested on cut roses and Lisianthus, such as Aspirin, soft drinks, light drinks, addition of chlorine, coins with or without copper in different dosages, and even cut flower preservatives were added to water.

Tests have shown that all the various remedies provide no benefit over the use of plain tap water. On the contrary, negative effects have been shown in some cases: Aspirin has a disastrous effect on the leaves of Lisianthus, and a high dosage of chlorine turns the leaves of Roses yellow. The only positive results came from specific products (preservatives and nutrients for cut flowers) and from a soda (they used a 7Up in the test): the latter improves tap water in terms of sugar content and acidity level.

The FloraHolland study however recommends using commercially available preservatives for cut flowers, following the doses indicated on the packages. In fact, these products prolong growth in vases, stimulate flowers to open, and help keep the colour alive longer; sugary drinks can give similar results, but it is much more difficult to dose them correctly.

STORING CUT FLOWERS: 6 RULES FOR LONG BLOOMS

To make cut flowers last longer, we simply need to make sure that we always keep the bouquet fresh and avoid rot, which is inevitable in standing water.

Here are 6 basic rules:

  1. Place the vase with the cut flowers in the coolest possible place in the house. Definitely not in the sun and away from heat sources. In winter we can move it, at least overnight, to an unheated room. Even outside the window, as long as the temperature does not drop below freezing. Putting two ice cubes in the vase of water in the morning and evening can also help reduce the temperature.
  2. The water in the vase should always be cool. Change it at least once a day: in summer even twice. Rinse the pot well to remove any plant debris, which may rot.
  3. When you change the water, shorten the stem by 1 centimetre daily. Use sharp scissors and cut obliquely, to increase the surface area and allow the stem to absorb more water.
  4. Insert only the stems into the water. Leaves tend to rot and therefore should be cut off.
  5. Wilted flowers should be removed immediately: they release harmful substances into the water that accelerate the wilting of other flowers.
  6. If you want to further "help" your bouquets, do not resort to alchemist's methods and use specific preservatives for cut flowers, which are dosed perfectly to help the vegetative development of the flowers cut.