Biodynamic planting, grounded in the sidereal Moon
A practical, plain-language guide to planning garden work by lunar rhythms: Root, Leaf, Flower, and Fruit/Seed days, plus transplanting windows — with sources and logic you can inspect.
How it works
This approach uses a sidereal reference for the Moon’s position, then classifies days by the element of the Moon’s current sign. Separately, we highlight transplant-friendly windows (often described as Moon in the arc from Gemini through Scorpio). This site is intentionally transparent: data sources, mappings, and rules are separated so you can adjust them.
1) Sidereal Moon position
We want a sidereal reference (not tropical) to determine the Moon’s sign/nakshatra for a given time and location. The goal is consistency and traceability of the underlying astronomical data.
- Source: sidereal Moon sign (and optionally nakshatra)
- Output: “Moon is in Sagittarius (sidereal)”
2) Map sign → element → day type
The biodynamic “day type” mapping commonly used: Fire→Fruit/Seed, Earth→Root, Air→Flower, Water→Leaf.
- Fire: Aries, Leo, Sagittarius → Fruit/Seed
- Earth: Taurus, Virgo, Capricorn → Root
- Air: Gemini, Libra, Aquarius → Flower
- Water: Cancer, Scorpio, Pisces → Leaf
The four biodynamic day types
Use these as planning “biases,” not rigid rules: they’re most useful when you need to choose between multiple good days.
Tomatoes, peppers, beans, peas, grains
Emphasis on fruiting/seed-bearing plants and activities that support flowering→fruiting.
Carrots, beets, potatoes, onions
Bias toward root development, cultivation, and direct-seeding of root crops.
Lettuce, spinach, kale, herbs
Great for leafy growth and many transplanting tasks, especially leafy starts.
Broccoli, cauliflower, flowers
Bias for blossoms and flowering crops; also commonly favored for transplanting certain brassicas.
Transplanting windows
A common guideline (as noted in your planning text) is that transplanting tends to be favored when the Moon is in signs from Gemini through Scorpio. This can be presented alongside day type so you can pick a “best fit” for the crop category and your schedule.
Favorable transplanting period (rule-of-thumb)
Moon in Gemini → Scorpio (ascending window in some biodynamic interpretations). In this window, prioritize transplanting when you can align with the crop’s day type (Leaf/Flower/Fruit).
- Leafy starts: aim for Leaf days inside the window
- Fruiting starts: aim for Fruit days inside the window
- Brassicas/flowers: aim for Flower days inside the window
When you’re outside the window
If you’re outside Gemini→Scorpio, you can still garden — just bias toward direct seeding, root-supporting work, pruning, or harvest for storage (depending on your tradition and local conditions).
- Direct seed roots on Root days
- Do maintenance/cultivation when it fits your weather
- Use the calendar as a tie-breaker, not a dictator
Calendar preview (mock data)
This is a layout mockup for a near-term feature: a month view that lists day type + transplant window, with a “sunrise-to-sunrise” note and location-aware times later.
| Date range | Day type | Moon sign (sidereal) | Transplant window | Practical notes |
|---|---|---|---|---|
| Jan 3–5 | Leaf (Water) | Cancer | Gemini→Scorpio ✓ | Great for transplanting leafy greens; water/soil moisture work. |
| Jan 6–8 | Fruit/Seed (Fire) | Leo | Gemini→Scorpio ✓ | Good for fruiting starts (tomato/pepper) if you’re transplanting early indoors. |
| Jan 13–15 (early) | Leaf (Water) | Scorpio | Gemini→Scorpio ✓ | Another strong leafy transplant window. Use weather + greenhouse reality. |
| Jan 15 (evening) – Jan 16 | Fruit/Seed (Fire) | Sagittarius | Outside window | Bias toward fruit/seed tasks, but many traditions say transplanting is less favored here. |
| Jan 17–19 | Root (Earth) | Capricorn | Outside window | Good for root focus and direct seeding where conditions allow. |
| Jan 28–30 | Flower (Air) | Gemini | Gemini→Scorpio ✓ | Transplant brassicas/flowers (depending on season); good planning + bed prep days. |
Get updates
Subscribe for new calendar releases, planting guides, and tool updates. (Mock form now; you can wire this to a simple email list later.)
FAQ
These are the questions we’ll answer clearly on the site as it matures.
Why sidereal instead of tropical?
Your note captures the core idea: sidereal references aim to track the Moon against fixed stars/constellations, which some biodynamic practitioners prefer for consistency in planting calendars.
Is this “scientific”?
This site can be honest about what’s astronomical (Moon position) and what’s interpretive (day-type guidance). The calendar is best used as a planning aid when you’re choosing between multiple workable days.
Does location matter?
Yes. The Moon’s sign transitions happen at specific times, and “which day it counts as” depends on time zone and whether you treat the day boundary as midnight or sunrise.
What’s coming next?
A location-aware calendar, a crop library, and a “what should I do today?” assistant that explains reasoning step-by-step (sidereal → element → day type + transplant window).