Agreed, just putting something in the description would help. Sometimes an upgrade that took forever to afford just didn't seem to do anything or raise the mana per second, so it would be good to know what they actually do.
Something I'm not sure is a bug - very rarely you get another blue square right after you click on a blue square, and it gives a much bigger bonus than usual.
Done!
And yeah, it's not exactly a bug, more a side effect of how the Enchanted Garden Plots work. It's possible to take advantage of this to earn lots of mana pretty fast, but it requires paying attention and having a deep understanding of how the game works, so we left it as is as a reward for players who work on figuring out how the game works. :)