floricide (n.)

"one who destroys flowers," 1842, from Latin floris, genitive of flos "flower" (see flora) + -cide "killer."

[S]urely there is cruelty and gross selfishness in cutting down for our own fleeting gratification that which would have ministered to the enjoyments of all for weeks or months. Frankly do I confess that I dislike a wanton floricide. He has robbed the world of a pleasure; he has blotted out a word from God's earth-written poetry. ["New Monthly Magazine" 1847]