1 Botanical Identity
- Latin name: Polygonatum odoratum (Mill.) Druce; common names — Solomon’s Seal, Yuzhu.
- Family: Asparagaceae, genus Polygonatum.
- Morphology: Arching stems (50–80 cm), alternate elliptic leaves; creamy tubular flowers May-Jun; blue-black berries Jul-Sep.
2 Natural Distribution & Agro-Climate
- Native to temperate Eurasia; China remains the primary commercial origin (NE, NW, N, E, Central, South China & Taiwan).
- Prefers cool, humid, semi-shaded forest margins (alt. 500–3000 m); intolerant of drought or direct sun.
3 Cultivation Practices
| Step | Key Points | Buyer Relevance |
|---|---|---|
| Propagation | Rhizome pieces (3–5 cm, ≥2 buds) ensure varietal uniformity. | Traceable origin lots. |
| Soil | Loose, humus-rich; pH 5.5–6.8; raised beds prevent waterlogging. | Lower microbial risk. |
| Shade Management | 50–70 % shading nets or under-canopy forestry. | Better appearance & polysaccharide retention. |
| Growth Cycle | 2 years to first harvest; peak yield in year 3. | Plan contracts 18-24 months ahead. |
4 Harvest & Primary Processing
- Rhizome lifting in late autumn after aerial parts wilt.
- Cleaning → steam-curing (95 °C, 1 h) to inactivate enzymes, enhance sweetness.
- Slice & low-temp drying (≤60 °C) to ≤13 % moisture.
- Grading by diameter, ring density & color.
5 Sustainability Notes
- Agro-forestry intercropping boosts land use efficiency and reduces soil erosion.
- Organic or GAP-certified farms increasingly available; request certificates during supplier audit.