If caves are getting biomes, maybe some existing certain crops, potable plants, trees and whatnot should be farmable in caves and have an actual affinity for growing in them.
Maybe something like stalagooms should be able to grow on tilled land and farmed but only underground rather than relying only on pots?
Maybe tubers and cabbage should all be able to grow underground?
MAYBE even growing certain crops that can actually be grown underground have a higher chance of LOSING quality, but a very minor chance to produce an offspring that is like a new plant that actually thrives in caves and when planted and cultivated has normal +,- mechanics.
example, beets can be grown underground but have a low chance of hitting a + quality increase,
when picking a beet crop underground you have a weird-beetroot-%-chance of it being harvested as White Beet or Raddish. This new vegetable, which has new stat gains and recipes, can be planted and cultivated only underground and regains its normal +,- quality increase mechanics