Grape seed

 can be planted in a vine trellis in the farming space on Witch Hill known as the Vineyard. To obtain these seeds, you must purchase them from the Merchant, after-which one can get some number of seeds back each time you harvest the fully grown crop. However, without using quality fertilizer, one cannot sustain the crop and will lose seeds each time. Grapes are an improvable crop, meaning they have a variety of quality levels and the seeds and resulting crop can be improved with fertilizer. For more informations, see farming.

Trading
Graine de Vigne