Let's try and collate all the knowledge we can (what's another word for glean...) from the new minigame.
Ticks are the time it takes for a plant to transition to the next stage. There are four stages once you put the seeds in the plot: Bud, sprout, bloom, mature. Not all plants move to the next stage at the same time, eg 5 of my 6 plants just went to bloom during this experiment but I had to wait until the next tick for the 6th one. So that means all plants must be at the same stage for a full tick before they move up to the next stage.
Plots are linked to levels. I have level 2 farms which gives me six plots. I think you can go up to 20. Each plant boosts CPS, the amount of which depends on the type of soil you use.
I just looked at CPS boosts across the 4 plant stages using "dirt".
Multiplier = 68.898quin %
Multiplier =69.515quin %
Multiplier =70.542quin %
Multiplier =72.597quin %
I did nothing else during this time so the only other increases in CPS can be attributed to century egg etc.
So, start experimenting with the soils and see what you come up with.