Milk Thistle — Growing reference
| Scientific name | Silybum marianum |
|---|---|
| Seed germination (days) | 7–14 |
| Soil temperature for germination (°C) | 12.8–18.3 |
| First harvest or flowering (days) | 120–180 |
| Measured from | Seed |
| Plant spacing (cm) | 61–91.4 |
| Mature height (cm) | 91.4–182.9 |
| Mature spread (cm) | 61–91.4 |
| USDA hardiness zones | 5–10 |
| Light | Full sun |
| Water | Low |
| Sowing method | Direct sow |
Growing directions
Direct sow 1/4 in deep in early spring; milk thistle germinates readily in cool, moist conditions and self-seeds vigorously once established. Plants become quite large and spiny — space generously and wear gloves when tending them. Monitor flower heads closely as seeds ripen quickly and can be scattered by wind; harvest heads when the fluffy pappus begins to appear but before seeds fully disperse. Dry seed heads on a tray, then thresh to separate the hard achenes, which are ground or extracted for their silymarin content in liver-supportive preparations.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0