Tapis de Fleurs
While we're on the topic of mosaics made with unconventional materials, here we have a giant flower rug. A site that I briefly skimmed told me that this takes over 700,000 begonias and is a early Brussels tradition. I know you wanna see it up close, so go check out a photoset on flickr. Not to disappoint, but it seems to be made from their petals, not from actual, planted flowers.