An ideal category image is 300px X 300px. Also, make sure the image is compressed to a 50% compression level on this website:
http://jpeg-optimizer.com/
Update Image
Images are compressed and resized to 600 X 600. Make sure you are starting with a square image that is at least this size please.
-alaska-white-poinsettia-1706713338.jpg)
-biancaneve-white-poinsettia-1706715594.jpg)
-superba-white-poinsettia-1706715921.jpg)
