Herbs are only used by the Monastery brewery to produce Beer. Spice fields will only produce Spices on islands with the requisite fertility, which only appears on southern islands.
The Spice farm is an Oriental Farm buiding that produces Spices, which are required to satisfy the Need for Food of Citizens, Patricians, and Noblemen. Each Herb field costs 50 Gold coins, bringing the total cost to 600 Gold coins. Spice fields require adequate Fertility.Produces Spices. The production chain for producing Herbs consists of a single Monastery garden with 8 Herb fields. Herb seeds can be purchased from Lord Richard Northburgh and planted on any northern island that has a customizable resource. Herb fields will only produce Herb on islands with the requisite Fertility, which only appears on northern islands. The Monastery garden is the only building with fields of size (3 x 2), and requires the most amount of fields out of any Farm building, requiring 8 fields to reach full productivity. Herbs are also used to supply Hekata and her Sister in the Old tree. The Monastery garden is an Occidental Farm building that produces Herbs, which are used to produce Beer.