When do flowers start to turn dead?

i just bought some fresh flowers from the grocery store and left them at this girls doorstep how soon will the flowers go bad? and it is night time

When do flowers start to turn dead?
In a case like that, 24 to 36 hours, if she cuts approximately 1/2 to 1 inch from the bottom of the stem and place it in the sugar water it will last a couple more days. :-)
Reply:If they aren't in water, not long. But I'm sure they will be fine when she finds them.
Reply:Flowers start to go dead the moment you break the stem

on the plant

Having them in water helps but its not the same

as the minerals and sugars found in the stem fluid

of the plant

My mother use to add a pinch of sugar to her flower vases

to extend the flowers life after death