Buying market flowers that actually open, not wilt by Tuesday
A bundle chosen for color alone often droops within a day. A little attention to the stems and the water fixes that.
What usually goes wrong
Most bundles from a market stall are cut early in the morning and then sit in a bucket of standing water for hours, sometimes with no fresh cut before they go home. The stems seal over at the bottom within a couple of hours out of water, which is exactly why a bunch that looked full and bright at the stall can be closing up or dropping petals by the second evening. People also tend to grab whatever has the loudest color, without checking the stems themselves. A stem that feels soft or slightly slimy near the cut end is already on its way out, no matter how good the bloom looks from a step back.
What to do instead
At the stall, press gently on a stem an inch above the cut. It should feel firm, almost like a fresh vegetable, not soft or spongy. Flowers that are still mostly closed, especially anything in the rose or ranunculus family, will usually last longer at home than ones already fully open, since an open bloom has less life left in it. Ask whether the bunch was cut that same morning; a lot of stall growers will tell you plainly, and it changes how many days you get.
Once home, the fix is simple and takes two minutes. Cut about an inch off each stem at an angle, under running water if possible, so no air gets sealed into the stem. Strip any leaves that would sit below the waterline, since leaves rotting in water are what actually cloud it and shorten the life of the whole bunch. Use a clean container, not one still slightly soapy or with old residue on the sides, and change the water every two days rather than just topping it off. Keep the arrangement away from a sunny windowsill or a spot near the stove, since heat pulls moisture out of the bloom faster than the stem can replace it.
None of this is about the flowers being special. It is about buying something that is still, quite literally, alive, and treating it that way for the short time it is in the room.