Growing Cardiocrinum giganteum var. yunnanense (Yunnan Giant Lily) from seed:

1. Seed Preparation
   • Breaking Dormancy: Yunnan Giant Lily seeds typically have a dormancy period, so they need “stratification” to break dormancy before planting.
   • Cold Stratification: Mix the seeds with moist sand or a damp paper towel, place them in a plastic bag, and refrigerate (at around 4°C) for 8-12 weeks.

2. Sowing
   • Sowing Time: The best time to sow is in autumn or early spring.
   • Soil Requirements: Choose well-drained, loose soil rich in organic matter with a pH between slightly acidic to neutral (6.0-7.0).
   • Sowing the Seeds: Scatter the seeds on the soil surface and lightly cover them with a thin layer of soil or vermiculite (no more than 1-2 mm), as the seeds need some light exposure to germinate.

3. Environmental Requirements

   • Temperature: The optimal temperature for germination is 15-20°C. Maintain stable conditions and avoid extreme temperatures.
   • Humidity: Keep the soil consistently moist but not waterlogged to avoid seed rot. Use a spray bottle to regularly mist the soil to maintain moisture.

4. Germination and Growth
   • Germination Time: Seeds may take several weeks to months to germinate, depending on environmental factors and the effectiveness of the stratification process.
   • Seedling Care: Once seedlings develop 2-3 leaves, they can be transplanted carefully, ensuring not to damage the roots.

5. Light and Fertilization
   • Light: Yunnan Giant Lily prefers partial shade and grows well in areas with filtered light or partial shade.
   • Fertilization: During the growing season, fertilize monthly with diluted organic fertilizer or slow-release fertilizer to promote healthy growth.

6. Transplanting
   • Timing: Once the seedlings grow larger (usually after 1-2 years), they can be transplanted into the garden or larger permanent pots. Ensure loose soil and suitable environmental conditions during transplanting.

7. Blooming
   • Yunnan Giant Lily generally takes several years to mature and bloom. Once mature, it will produce tall flowering stalks with beautiful, trumpet-shaped flowers.
As a perennial, the Yunnan Giant Lily requires a long period to reach maturity, so patience and attentive care are essential.