How long does it take plants to grow?

Solution 1:

According to the Game Wiki:

It will take approximately 24 hours before it bears fruit. This is tied to real-time but can be manipulated if the system clock is manually changed. Harvest the field. Leave it for 2 days or more and they will potentially wither. Using a fertilizer will either speed up the process or increase the outcome of the plant.

This guide also claims the same:

Growing plants and vegetables uses real-world time, so this isn't a quick process. Usually, it takes a whole day for something to fully grow, and another day for it to die

It seems the amount of time for each crop is the same, with the only thing changing the growth time being the speed fertilizer - and I suppose manipulating your system clock as well, but that's not an in game solution. I found a few sources such as this one claiming the speed fertilizer cuts the time in half:

I've read that it cuts the growing time in half, but not the harvest/decay time