I've added a tooltip in my development version that should help explain that. I'll ensure the formula is included as well. I'm working on some additional features and may push out another release tomorrow; if not, I will do so this weekend. Thank you!
That's when you buy a larger farm. Wait a bit until you have more exp and unlock more plots on the next farm. It takes a few iterations before you can get to those high-level vegetables.
Farm plots expand based on the experience you have when you purchase the new farm. Experience gain is boosted by the amount of knowledge you have when you gain it. There's a decent number of 'hidden' mechanics that I've been trying to find a good way to display to the user without cluttering up the UI.
