Instructions
Find the Item Seller in your home village, the starting area for all new hunters. She is standing next to the armory.
Buy needleberry seeds from the Item Seller, then travel to the farm that is in or near your home village.
Talk to the cat to bring up the farming options. Select "Cultivate" and "Seed" from the list, then choose a fertilizer. Fertilizing your crops increases the crop's yield.
Wait for the crops to mature, which takes about half a day, then approach the field row and harvest the crops. The harvested items appear in your inventory.