Let's say you made a crop (or, in this case, literally just copy-pasted the cranberries art into a new png). When it grows, you notice some weird floating pixels on one side or see that it's been cut off on the edge. What happened? You didn't line the different stages up right.
This crop seems fine at first glance. It's got all the correct stages and everything fits in 128 x 32 pixels, the correct size for a crop.png. But each stage needs to fit neatly inside its proscribed 16x32 pixel area and that is not the case here. How to solve?
Easy: just get a template! If one isn't available you can make your own by coloring squares the right size and alternating. (And if you do make your own, it would be kind to upload them to this wiki...).
Here's one for crops:
Now all you have to do is put the template on one layer and use it as a guide as to where things go. It helps you see if your sprites are properly lined up.
By using the template, it's suddenly very obvious where our crop stages don't line up correctly.
Now the crops are lined up correctly. :) Each one fits in its own 32-pixel space, and they've also been moved down one pixel to keep stage 4 from being bigger than one square of dirt for aesthetic reasons.
When the crops are in the right place, just delete the template layer or make it invisible and save your png with a transparent background.