Ye Olde Valentine: how old is Valentine’s Day and when did giving flowers become a part of the tradition of the holiday?

The time will come
when, with elation
you will greet yourself arriving
at your own door, in your own mirror
and each will smile at the other's welcome,

What’s her top suggestion for communicating love this Valentine’s Day while also avoiding the environmental disaster that is the global cut-flower trade? Small flower farms just like ours, of course!