The corn poppy season is rapidly coming to an end here: this might be the last substantial bouquet I get this year.
If you go out into the garden during the middle of the day and pick poppy flowers, they soon wilt. The poppy literature mentions two ways to avoid this wilting, and Celia Thaxter suggests a third. The two ways usually mentioned are 1) to sear the cut end of the stem in a flame; I have not tried this method. And 2) to pick the unopened buds the evening before the flowers are wanted. As the buds develop they hang down; when they are about to open, they become upright. They can be gathered as soon as they become upright. This is perhaps the most charming way to gather poppies, because the cut buds can be presented the night before, then the recipient has the pleasure of watching the buds pop open and drop the hairy calyces on the table top the following morning. Once the calyx falls, the crumpled petals of the flower slowly expand: it's hard to describe how beautiful they are at this stage. So much about these poppy flowers is improbable: the thin, flexuous stems; the comparatively big expanded flowers; the intense color; the delicacy of the pollen dusted dome of anthers at the center of the blossom; the crepe and satin like quality of the expanding petals and the pepper shaker at the center of the flower. Any child can grow them, and I'd be concerned about any adult too sophisticated to appreciate them.
Now here's the other method for picking them, a method suggested by Celia Thaxter over a century ago: pick the opening flowers at sunrise. I've done this three times this year; the two times I picked the opening flowers at about 6 A.M. (sunrise here is at about 5:45 now) they held up beautifully and developed fully. The one time I picked them at about 7:30 A.M. they did not last.
It's too late to plant poppy seed and expect to get great results, but it's not too late to start reading Celia Thaxter's An Island Garden.