noun
wasteland; area overgrown with weeds
Refers to a place where mugwort (蓬) and other weeds grow thickly, often implying neglect or desolation. A somewhat literary term.
かつての庭園は今や蓬生と化している。
The former garden has now turned into a wasteland overgrown with weeds.
蓬生の中に古い祠がひっそりと立っていた。
An old shrine stood quietly in the weed-choked field.
荒地 is a more common word for wasteland or barren land, while 蓬生 specifically evokes an image of mugwort and weeds taking over a formerly tended place.
Compound of 蓬 (yomogi, 'mugwort') and 生 (u, 'grow'). The reading う is an older nominal form of the verb 生える (haeru).