Don't tell me that February produces spring or summer flowers elsewhere in the world because the first mention of Valentine's Day was in 1415 by the Duke of Orléans, while imprisoned in the Tower of London.
"Je suis desja d'amour tannéThis is often quoted as the first Valentine but in reality he wrote poetry with several references to Saint Valentine, generally contrasting the sunshine and the mating of birds with his own sorry state in prison. Now, in the 15th century Europe, you can be sure they weren't importing flowers from warmer countries. You can also be sure that there was little warm sunshine over the Tower of London, nor mating birds in mid-February.
Ma tres doulce Valentinée…"
"For this was on seynt Volantynys dayThis was an entirely fictional account of a make-believe tradition, and was written to mark the anniversary of the engagement of Richard II to Anne of Bohemia. Chaucer wrote a love poem every May. May! We may be getting somewhere! There is a Saint Valentine, a Bishop of Genoa from about 295 whose memorial day is 2 May. Confusion reigns, and it was assumed in hindsight that Chaucer was referring to 14 February because there were two different martyrs called Valentine and whose commemorative feasts were 14 February.
Whan euery bryd comyth there to chese his make."
The more modern tradition of sending greetings on 14 February became popular in 1797 with the publication of "The Young Man's Valentine Writer" but it wasn't until postal services became widely available to all that it really took off.