Looking to give a bouquet of flowers that won't cost the Earth (literally, those things travel miles!)  What about a watercolour bunch, that will last a lifetime?
 
Perfect to say 'You make my day, I hope these make yours', or 'I think the world of you, so I decided to decrease my carbon footprint and not buy imported flowers, but bought you this hand-painted, original, one of a kind card instead'...
 
The card measures 5" x 4", so plenty of room, whatever you decide to write.