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.
-spring-blooming-1659450073.jpg)
-hidcote-blue-herb-1665431041.jpg)
-munstead-herb-1665579595.jpg)
-vegetable-1657202233.jpg)
