Also known as: Yang Earth · Mountain Earth
Wu is yang earth, classically the great mountain (城牆之土). It is the firm wall, the embankment that contains rivers, the bedrock under the city. Wu Day Masters present as steady, conservative, trustworthy, slow to anger and slow to change — but once their position is set, very hard to move. They make natural protectors, guardians of family, and stewards of long-term institutions.
Wu pairs with 癸 in 戊癸合化火, where great mountain meets gentle dew and ignites distant fire — often glossed as the chart of late-blooming insight. Wu fears too much wood (forest cracking the rock) and welcomes water in moderation (rivers carving valleys productive).