Blue bouquets: how long the blue keeps
Vase life inside one blue bouquet is rarely even. Two stems standing in the same jug can be five days apart in how long they hold their shape, which is why a bunch of this colour often looks tired on one side and untouched on the other by the end of the week.
Nothing about the stems tells you that when they arrive.
The long end and the short end
Eryngium outlasts everything else in the bucket. The head is stiff and papery rather than fleshy, it does not bruise in a bag, and once the water runs out the stem dries where it stands and keeps most of its steel blue. Anyone who likes keeping flowers ends up with these in a dry jug months later.
Delphinium sits at the opposite extreme and needs to be understood before it is bought. The colour comes from many small florets on a tall spike. They open from the bottom upwards and drop in the same order while the top of the spike is still opening. The plant therefore looks alive and busy while quietly covering the table beneath it. In a warm room this happens faster, so the vase belongs somewhere a daily handful of fallen florets is not a problem.
Iris is the fast one. A tight bud opens within a day of arriving, the open flower holds for about two days, and a good stem carries a second bud that takes over as the first collapses.
Hydrangea has a habit worth knowing. It drinks through the head as well as the stem, so when it flags, and it flags suddenly, the head can be laid in cool water for half an hour and usually comes back. A stem that has gone soft along its whole length will not.
Tinted stems ask for one extra habit
Colour taken up through the cut keeps leaching back out. The vase water tints within a day, and pale flowers sharing that water pick up a faint cast at the petal edge, so the water gets changed more often than you would bother with for a plain white bunch.
Sprayed heads are the simpler case, since the paint sits on the outside of the petal and stays put unless you mist the flowers or leave them where rain can reach them through an open window.
Direct sun shortens the colour on both. Applied blue fades faster than a grown pigment, and a windowsill in summer takes the edge off it within days.
Buying with all this in mind
Ask what is carrying the blue before you agree on the price, because a bunch built on eryngium and hydrangea and a bunch built on delphinium will look nothing alike a week later.
Recut the stems on arrival and keep the water shallow for anything hollow-stemmed. Delphinium holds better in a jug filled a third of the way up than in a deep vase.
Blue bouquets reward a cool room more than most colours, since heat pushes the short-lived material through its cycle in half the time. If the flowers have to wait at a reception desk in Shanghai for part of the day, that alone can cost the delphinium a day of its life. Ask for a delivery slot close to the hour the recipient is actually there.
