Mod raws to underground plants grow in all seasons.
The plantworks should be in a soil area. Either near the surface, a previously flooded digging or the caverns.
While it should usually be the first works put in operation security wise that is often a bad location. During the initial digging just setup a temporary plot of plump helmets for food and drink. Later dig back up through the aquifer in a safer location (one with several layers of soil above so roof collapses don't happen) and build the complete works.
If it can be safely put near the surface a windmill and Millstone can replace the Quern. Otherwise water flow is needed to power a millstone. See Millworks Construction for a powered millstone.
A screw Press can also be added to press rock nut oil.
The entire dig (outside the waterwheel room) is 19x13. If the aboveground and output stockpiles are left off 19x9.
Farm plots are 1x7 to match fertilizer stacks.
run the following in DFhack so seeds will not be lost.
seedwatch MUSHROOM_HELMET_PLUMP 10
seedwatch GRASS_TAIL_PIG 10
seedwatch POD_SWEET 10
seedwatch GRASS_WHEAT_CAVE 10
seedwatch BUSH_QUARRY 10
seedwatch MUSHROOM_CUP_DIMPLE 10
seedwatch start
Skills Required
Custom Profession: Food Guild Farmer (FF)
Inputs
Stockpiles and links
Create two SeedsUnderground stockpiles one with no barrels and one with barrels. Give from the one with no barrels to the one with barrels.
A Bag stockpile and a Barrel/Pot stockpile which give to the Millstone and the UndergoundSeeds stockpiles can help facilitate jobs.
Job Setup
Millstone
Use workflows
Create a standard Mill Plants job and set to repeating. Hit Alt-A. Then m and select the appropriate plant material. Hit alt-w and shift-A and set an appropriate constraint. Repeat for each plant type available to be milled (Cave Wheat -> Flour, Sweet Pods -> Sugar, Dimple Cups -> Dye, other plants as applicable).
Do the same for Mill plant into slurry but choose pig tails or other slurry plant as the material.
Farmers workshop
Above Ground Crops
Look for Hemp (food & clothing) on the surface.
Rope seed, flax, jute, cotton, ramie, kenaf for clothing
blade weed, hide root, silver barb for dye