It is known that if you add aspirin or sugar to the water for a bouquet, the flowers will last longer and will please the eye longer.
There is a nuance here. You need to understand what kind of flowers are in the bouquet. In addition, aspirin and glucose are just conventions that do not replace the care of cut plants.
By the way, the most durable flowers among florists are tulips, roses, hyacinths and some others, for example, carnations, but this is not the most festive option.
These are the most popular flowers of early March. And to extend their durability, it is enough to renew the cut on the stem once every 2 days (not diagonally), add ice to the water, change this very water every day, and put the flowers in a cool room at night. So tulips will last up to 14 days. Sugar or tablets can be omitted in this scenario.
First, you need to remove any extra leaves on the stem, at least anything that might come into contact with water. The stem is cut at an angle of 45 degrees, and the water is changed at least once every 2 days. As for aspirin, with such care it will not harm (and nothing more).
These flowers are not trimmed at all, but are placed in a vase directly with the bulb. In order for the flowers to last as long as possible, you will also have to change their water twice a day.
As for the mentioned folk preservatives for flowers, according to flower growers, they are not able to extend the life of flower bouquets. This can be achieved only by caring for flowers every day.