So, I ran into the problem of getting a lot of herb seeds while going through the ancestral grounds. I got to my brand new house, hoping that I could plant them, but to my dismay the plots were crop plots, and herb plots only exist in specific housing, housing in which you can only own one house so far.
So I am suggesting that, with a skill perhaps, you, as your in game character, will be able to change the plot, so it could grow herbs or crops. Not both mind you, just one or the other.