- Season: Biennial
- USDA Zones: 5 - 10
- Height: 40 - 55 inches
- Bloom Season: Late spring to mid summer
- Bloom Color: Pink
- Environment: Full sun
- Soil Type: Grows in any type of soil, pH 6.6 - 7.8
- Temperature: 55 - 70F
- Average Germ Time: 7 - 14 days
- Light Required: Yes
- Depth: 1/4 - 1/2 inch
- Sowing Rate: 1 - 2 seeds per plant
- Moisture: Keep seeds moist until germination
- Plant Spacing: 24 - 36 inches
Milk Thistle (Silybum Marianum) - Milk Thistle seeds grow easily and produce a hardy biennial that is native to the Mediterranean area and has naturalized throughout North America. It is very impressive as an ornamental herb plant. It is tall and stately with large, mottled, spiny foliage that contains a milky sap-like substance and large, thistle-like heads of rose-pink flowers. Milk Thistle herb plants do re-seed themselves, so it is recommended to deadhead the flowers before they set seed. Other common names for this herb plant are Mediterranean Milk Thistle, Marian Thistle, St Mary's Thistle and Holy Thistle.
Milk Thistle is a well-known medicinal herb with a long history of use in the treatment of liver and gallbladder ailments. It is the Milk Thistle seeds that are used medicinally, and they contain silymarin which is a flavonoid. The Milk Thistle herb may have a protective and regenerative effect on liver cells. As a nutritional supplement to support liver function, the seeds can be ground and added to hot cereals or other whole grain dishes.
How To Grow Milk Thistle From Herb Seeds: Grow Milk Thistle seeds directly in the herb garden. Prepare a seedbed and sow the herb seeds in the spring when temperatures have warmed. The Milk Thistle plants prefer full sun, but they are not picky about soils. They are also tolerant of dry and wet soils.