Good morning, @Hime,@Juji
What is your intention to drop the herb in places that are low and completely irregular for the farm?
Look:
Atelia Fortress, Atelia Refinery, Garden of Spirits: Lv 100-104 - Low XP level and low adena drop. It's empty, nobody's farm;
Giant’s Cave: Lv 99-100, low are level and, low XP drop, low drop of adena and completely unsuitable for farm;
Harnak Underground Ruins: Lv 85-90, completely uneven for the farm;
Cruma Tower: Lv 40, it is ridiculous to drop herb here 1-85 is done in NPC quests.