So I ran a few numbers...



The time to plant any seed is approximately 100 steps.



You can grow 13.44 plump helmets per year (rounds off to just 13- growers don't cycle through years according to the wiki). This means that per season, if plants grow in stacks of one, one farm tile will produce 3.36 plump helmets. Since a dwarf will eat 2 of something per season, and drink 4 of something per season, this means one farm plot can produce enough to sustain a dwarf for exactly one season, leaving one unit of booze left over.



So at the bare minimum, you should have one farm plot for each dwarf in your fortress, if you have unskilled growers and are growing only plump helmets.



Meaning, for a fortress 200 strong, you need four farm plots of the maximum size possible.



However, with legendary growers, the average stack size is roughly 4. This means that each farm tile can support roughly 4 dwarfs. So for a fortress 200 strong, you need only one farm of the maximum size.



Quarry bushes are a different matter. One tile can produce 6 quarry bushes a year, 2 per season. Thus, if they grow in stacks of one, you get enough to support 5 dwarfs a season. However, quarry bushes don't grow during the winter. You can either grow plump helmets during this time, or you can grow all you need during the other seasons.



As it turns out, with legendary growers churning out quarry bushes, you can meet your entire fortress's food needs with 13.3 farm plots growing quarry bushes at 4 stacks each time, in a year. So if you had a 14-tile farm plot and a legendary grower, you can meet the food needs of a fortress 200 strong indefinitely. (to meet booze needs, a 13-tile year-round farm growing plump helmets will work, provided your dwarfs didn't eat the plump helmets)





Don't give me that look. I was bored. <>.<>