I am not a huge fan of cut flowers unless they have come straight from my garden. However, at this time of the year, with Mother's day looming and little to pick in the garden, then shop-bought flowers may be your only option. I have often been asked about the many old wives' tales about keeping your cut flowers looking fresh. Well here is some old man's wisdom instead!
As soon as a flower is cut it's access to food and water via a root system is cut too, but it can continue to draw water and nutrients up through the cut stem. On first cutting, air can enter the stem and cause a sort of embolism that prevents further absorption. Re-cutting the stems when you first get the flowers home can remove any trapped air and help the flowers to re-hydrate.
Put some lukewarm water in the sink. Using sharp scissors, cut 1-2 inches off the stems underwater at a sharp angle. Then remove any foliage that will sit below the water line in the vase.
Often flowers are provided with a small sachet of ''flower food'' to add to the water. This is most likely to contain some sugar, some acid and some bleach...sounds harsh! The sugar is a feed, the acid is to kill off bacterial growth and the bleach to maintain a ph balance in the water. All this is designed to keep your flowers in tip-top condition. If you don't get that little sachet then a drop of apple cider vinegar and a small teaspoon of sugar will do a good job too. Make sure that you change the flower water every 3 days and you can also re-cut the stems if you don't mind rearranging the flowers. Another good tip to prolong their life is to put the flowers somewhere cool overnight such as the garage or porch.