nocturnal potatoes?

[jasta85]

So, I built an indoor potato farm (left the soil ground and built a wall around it).  The potatoes said they would not grow without light so I built a sun lamp, but at night time it says "Not growing now (night time)".  Do potatoes go to sleep or something at night?

[Tasty]

Yes, I believe all harvestable plants, possibly all plants, stop growing at night to prevent non-stop round-the-clock production for balance reasons.

[Evelyn]

The word you are looking for is "Diurnal"

[ItchyFlea]

You should download Alpha 8e which changes that text slightly to clarify why plants aren't growing at night. You can get it through the download link you got when you first bought the game/when Alpha 8 was released.