Some sticker sketches. (CLICK TO ENBIGGIFY.)
Carrot for rabbit festival, ribbon for festival places, heart for February, boots for February, the speedup/slowdown growth arrow, stopgrowth x, crappy trowel sketch, crappy watering sketch, crappy seed sketch.
I kind of feel like you should be allowed perhaps more than one sticker. Because, a sticker like a "speed up growth" sticker would only be useful while it's growing! :O Unless the sticker could be a one-use item and dissappear when placed on the cert.