Wu Earth Day Master (戊, Yang Earth)
Quick answer: Wu (戊) is the fifth of the ten Heavenly Stems: Yang Earth. You have a Wu Earth Day Master if the stem of your day pillar is Wu. The Di Tian Sui calls Wu "solid and heavy, centred and upright". Its commentary pictures Wu as the earth of hills and ridges — and explicitly says Wu is not city walls or embankments. That image is a way to remember the stem's nature, not a verdict on anyone's personality.
Not sure of your Day Master? Find it from your birth date, or calculate your full chart.
The classical image: what the Di Tian Sui says
The Di Tian Sui (滴天髓) is traditionally attributed to Jing Tu of the Song dynasty, although its authorship is uncertain. It describes each stem in a short verse. This is its verse on Wu:
戊土固重，既中且正。靜翕動闢，萬物司命。水潤物生，火燥物病。若在艮坤，怕衝宜靜。
"Wu earth is solid and heavy, centred and upright. At rest it gathers in, in motion it opens out; it presides over the life of all things. Moistened by water, things grow; parched by fire, things sicken. Seated in Gen or Kun, it fears clashes and prefers stillness."
— Di Tian Sui, "天干論", text as in the Di Tian Sui Chanwei (ctext.org). Wikisource variants include 萬物司合 and 若在坤艮. Translation: PillarChart editorial team.
Line by line:
- "Solid and heavy, centred and upright" (固重，既中且正). Wu is the high, firm form of Earth. The Chanwei original note says: 「戊土非城牆堤岸之謂也，較己特高厚剛燥，乃己土發源之地」 — Wu earth does not mean city walls or embankments; compared with Ji it is higher, thicker, firmer and drier, and is where Ji earth originates.
- "At rest it gathers… in motion it opens." A cosmological picture of earth storing and releasing, not a personality checklist.
- "Moistened by water… parched by fire." Climate language: water moistens earth so things grow; fire dries earth so things sicken. This is the same climate logic the Qiongtong Baojian applies month by month.
- "Gen or Kun… fears clashes." Gen and Kun are the earth trigrams / directions associated with earth places in some readings. The verse prefers stillness over clash when Wu sits there.
Wu is not a great wall
Wu is sometimes pictured in English as a city wall or a great wall. The commentary rules this out:
戊土非城牆堤岸之謂也，較己特高厚剛燥，乃己土發源之地
"Wu earth does not mean city walls or embankments; compared with Ji it is especially high, thick, firm and dry, and is the place where Ji earth originates."
The Wikisource edition calls Wu "earth of hills and ridges" (山岡之土，非城牆之謂). If you want a picture, high ground fits the text better than masonry. The same correction appears on our Day Master calculator.
Yin, yang and the Earth element
Wu and Ji are the two forms of Earth. Wu is yang (high, firm, relatively dry); Ji is yin (low, moist, field soil).
| Ji | Wu | |
|---|---|---|
| Polarity | Yang Earth | Yin Earth |
| Classical image | Earth of hills and ridges (山岡之土) — not city walls | Earth of fields and gardens (田園之土) |
| Di Tian Sui opening | 戊土固重 "solid and heavy" | 己土卑濕 "low and moist" |
| Main qi of the branch | 戌 Xu (Dog), also strong in 辰 Chen | 丑 Chou (Ox), 未 Wei (Goat) |
| Also hidden in | 巳 Si, 寅 Yin (among other qi) | 午 Wu (among other qi) |
| Combines with | 癸 Gui | 甲 Jia |
Read the partner page: Yin Earth (Ji).
Season and climate: why your birth month matters
The month branch tells you the season Wu was born into, and so how much support it starts with. In the seasonal scheme of the Sanming Tonghui, Earth is:
| Season (month branches) | Earth's state | What it means for Wu |
|---|---|---|
| Spring (寅 Yin, 卯 Mao) | Dead 死 | Out of season; wood is Prosperous |
| Summer (巳 Si, 午 Wu) | Strong 相 | Nourished by fire |
| Sixth month (未 Wei) | Prosperous 旺 | Earth's own season in this text |
| Autumn (申 Shen, 酉 You) | Resting 休 | Spending itself on metal |
| Winter (亥 Hai, 子 Zi) | Trapped 囚 | Held back |
The table follows the Sanming Tonghui text, which places Earth's season in the sixth month. The other Earth months (辰, 戌, 丑) are treated in more than one way across schools. See Five Elements.
Climate adjustment in the Qiongtong Baojian
The Qiongtong Baojian (窮通寶鑑) reads every Day Master month by month, asking first whether the chart needs warming, cooling or moistening. Its section on Wu in a key season opens:
三春戊土，无丙照暖，戊土不生，无甲疏噼，戊土不灵，无癸滋润，万物不长。正二月先丙后甲，癸又次之。
"In the three spring months, without Bing to warm it Wu earth does not live; without Jia to open it Wu is not responsive; without Gui to moisten it, nothing grows. In the first and second months the book puts Bing first, then Jia, with Gui next." — Qiongtong Baojian, 三春戊土 (Wikisource). Translation: PillarChart editorial team. Climate / adjustment lines only; the book also contains fixed fortune pronouncements, which we do not reproduce.
For other parts of the year, the book's climate recommendations for Wu include the following (paraphrased):
- Early summer (巳 Si): Yang rises; the book does not fear fire as much, and puts Jia first to open the earth, with Bing and Gui as assistants (「先用甲疏噼，次取丙癸为佐」).
- Seventh month: Cold begins to appear. The book puts Bing first, then Gui, with Jia next (「先丙后癸，甲木次之」).
- Tenth month: A little yang returns. The book takes Jia first and Bing next — without Jia the earth is dull; without Bing it is cold (「先用甲木，次取丙火」).
These describe what one classical method looks for, given the season. They are not predictions, and other methods may weigh the same chart differently. Where schools disagree on a rule, see How we calculate your chart.
Is your Wu Earth weak or strong?
Three questions decide it, in this order: season (the month branch), roots (Wu among the hidden stems, especially in 戌 Xu, 辰 Chen, 巳 Si or 寅 Yin), and support from other stems (more Earth, or Fire as resource). Our calculator scores this with a published point method. Here are two Wu charts it produced:
A strong Wu: Chicago, 2 July 1988, 10:00 (open)
- Day Master:
- Yang Earth (Wu 戊) · Read more about Wu Earth
- Strength:
- 93% · strong (9.3 of 10 points)
Born with month branch Wu 午, when Earth is in a supportive season on our reading, with roots / companions visible in the pillars (戊辰 戊午 戊午 丁巳). Score: 93%, strong (9.3 of 10 points).
A weak Wu: Chicago, 11 March 1981, 10:00 (open)
- Day Master:
- Yang Earth (Wu 戊) · Read more about Wu Earth
- Strength:
- 27% · weak (2.7 of 10 points)
Born with month branch Mao 卯, when Earth is out of its best season on our reading, with limited support among the stems and hidden stems (辛酉 辛卯 戊子 丁巳). Score: 27%, weak (2.7 of 10 points).
For what weak and strong mean in general, see Weak Day Master and Strong Day Master. The hidden stems page explains the roots table behind those scores.
Favourable elements. Which element a Wu chart is said to "need" depends on its season, its strength and the reader's method, so there is no single answer for all Wu Day Masters. Our calculator doesn't output a favourable element.
How Wu interacts with the other nine stems
The Yuanhai Ziping names the Ten Gods using Jia as its example, then the same generating / controlling logic is shifted to any Day Master. So for a Wu Day Master:
| Stem | Element | Relation to Wu | Ten God | Notes |
|---|---|---|---|---|
| 甲 Jia | Yang Wood | Controls Wu | Seven Killings (七殺, also 偏官) | |
| 乙 Yi | Yin Wood | Controls Wu | Direct Officer (正官) | |
| 丙 Bing | Yang Fire | Produces Wu | Indirect Resource (偏印; also 倒食, 梟神) | |
| 丁 Ding | Yin Fire | Produces Wu | Direct Resource (印綬, i.e. 正印) | |
| 戊 Wu | Yang Earth | Same element, same polarity | Friend (比肩) | |
| 己 Ji | Yin Earth | Same element, opposite polarity | Rob Wealth (劫財) | |
| 庚 Geng | Yang Metal | Wu produces it | Eating God (食神) | |
| 辛 Xin | Yin Metal | Wu produces it | Hurting Officer (傷官) | |
| 壬 Ren | Yang Water | Wu controls it | Indirect Wealth (偏財) | |
| 癸 Gui | Yin Water | Wu controls it | Direct Wealth (正財) | Combines with Wu (戊癸合) |
Wu and Gui combine. Wu–Gui is one of the five standard stem combinations. Our calculator doesn't model combinations.
Wu and wood. Wood controls earth. Whether Jia/Yi help or over-control a Wu chart depends on season (opening vs over-control) and the rest of the structure.
Ten Gods are labels relative to the Day Master, not personality verdicts. For the naming logic in general, see How we calculate your chart.
Common misconceptions about Wu Earth
- "Wu is my zodiac year element." Day Master ≠ year stem. See What is my Day Master?.
- "Wu people are all stubborn mountains." The ridge image describes the stem, not the person.
- "Wu is a great wall / city wall." This is the image the classics reject. See the section below.
- "Wood is always bad for Wu." Spring sections of the Qiongtong Baojian need Jia to open Wu. Seasonal opening is not a blanket ban on wood.
How modern readers describe Wu Earth
Modern guides often associate Wu with steadiness, reliability and slow movement, extending the high-ground image. Some also mention inflexibility. These are interpretations built on the classical image, not statements from the classical texts. You may recognise yourself in them or not. Neither result says anything about what will happen to you.
Frequently asked questions
Is Wu Earth yin or yang?
Yang. Wu is Yang Earth, and its yin partner is Ji.
What element is good for a Wu Earth Day Master?
It depends on the season and the chart's strength. There is no single answer. The Qiongtong Baojian recommendations above are one classical climate method; a strength-based reading would favour resource and companions for a weak Wu, and output, wealth and power for a strong one. Our calculator doesn't output a favourable element.
Which stem combines with Wu?
Gui (癸, Yin Water). Wu–Gui is one of the five classical stem combinations.
Is a Wu Earth Day Master the same as being born in a Earth year?
No. A Earth year means the year stem is one of the two Earth stems. A Wu Day Master means the day stem is Wu. You can have either without the other.
How do I find out if my Day Master is Wu?
Use the Day Master calculator. You only need your birth date (and whether you were born between 23:00 and midnight). The full chart also shows whether your Wu is weak or strong.
Why do some sites call Wu a "mountain" or "great wall"?
A mountain ridge has support in the Wikisource note (山岡之土); a great wall does not. "Great wall" / city wall is a popular English image that the Di Tian Sui Chanwei commentary explicitly rejects. Prefer high ground over masonry.
Next steps: Calculate your full chart to see your Wu's season, roots and strength score, or read about the hidden stems that give it roots.
Related
What is my Day Master?: all ten stems
Example charts you can audit · Ten Gods · Learn where to start
Sources
- Di Tian Sui Chanwei (滴天髓闡微), "天干論", verse on Wu and original note, Chinese Text Project: https://ctext.org/wiki.pl?if=gb&chapter=126492
- Di Tian Sui (滴天髓), 輯要 edition with notes, Wikisource: https://zh.wikisource.org/wiki/滴天髓
- Ziping Zhenquan Pingzhu (子平真詮評註), yin–yang pairing of stems, Chinese Text Project: https://ctext.org/wiki.pl?if=gb&chapter=974137
- Yuanhai Ziping (淵海子平), Ten Gods naming logic, Wikisource: https://zh.wikisource.org/wiki/淵海子平
- Sanming Tonghui (三命通會), 卷二, seasonal states, Wikisource: https://zh.wikisource.org/wiki/三命通會/卷二
- Qiongtong Baojian (穷通宝鉴), Wu seasonal sections (三春戊土 and related), Wikisource: https://zh.wikisource.org/wiki/穷通宝鉴
- Example charts: computed by our engine (
bazi-lichun-jieqi-tst-v1); see How we calculate your chart
Translations: PillarChart editorial team.
BaZi is a traditional Chinese cultural practice. This page describes what classical texts and practitioners say; it is for reflection, education and entertainment, and is not medical, legal, financial or psychological advice. Different schools may read the same chart differently.
Last updated: 2026-10-07