The Wormwood is a plant added by Witchery. This plant is used in several Brazier conjuration recipes. Wormwood grows in stages, and can eventually grow to two blocks high. Each block can be individually harvested. A fully grown Wormwood plant will drop 1-4 Wormwood Seeds and a single Wormwood item. Wormwood Seeds must be planted on tilled farmland.
Creation of Wormwood Seeds requires Wheat Seeds, 4 Wispy Cotton, 4 water blocks, and a Mutating Sprig. The Wheat seeds must be planted in the center of a 3x3 block area. In each of the corners, dig a 1 block deep hole and put water in said hole. Then, put Wispy Cotton on all adjacent sides of the Wheat plant. Finally, use a Mutating Sprig on the Wheat and it will transform into a Wormwood plant. The Wispy Cotton will disappear, though the water will not.