Milk Thistle

Silybum marianum

Seeds per pack ~ 40  

Germination: 98% (Packed for 2025)

Origins & History

Common names include Milk Thistle, Saint Mary’s Thistle, and Scotch Thistle is a Mediterranean native with a long history of cultivation dating back over 2,000 years. Widely grown throughout Southern Europe, North Africa, and Western Asia, it was prized in ancient Greek and Roman medicine for supporting liver health and digestion. Over centuries, it spread across Europe and into the New World, where herbalists and farmers preserved its value as a resilient, culturally significant medicinal plant. As an heirloom variety, Milk Thistle embodies both historic agricultural traditions and ongoing use in folk remedies.

Appearance & Characteristics

Milk Thistle is a striking biennial plant that can grow 3–6 feet tall. Its spiny, lobed leaves are marbled with white veins—legend holds that these white streaks were caused by the Virgin Mary’s milk, giving the plant its name. In the second year, it produces large, purple, thistle-like flower heads surrounded by sharp spines. The seeds, encased in silvery bracts, are the most commonly harvested part for medicinal use.

Culinary Uses

Though not as widely used in kitchens today, parts of Milk Thistle were historically consumed as food. The young leaves, with spines trimmed, can be eaten raw or cooked like spinach. The stems resemble celery when peeled, and flower heads can be prepared like artichokes. Most commonly, the seeds are roasted for tea or ground into powders and extracts, prized for their liver-supporting compounds.

Growing Tips

Milk Thistle thrives in full sun and well-drained soil. It is highly adaptable, tolerating poor soils and dry conditions, making it suitable for Zones 5–9. Sow seeds directly outdoors in spring after the last frost, planting them about ¼ inch deep. Space plants 18–24 inches apart, as they grow large and need room. For a continuous patch, allow some plants to reseed naturally.

Harvesting Guidance

Milk Thistle matures in its second year. Harvest leaves for culinary use when young and tender. The flower heads, if desired, are gathered before fully opening. For seeds—the most valuable part—wait until the flower heads turn brown and dry on the plant. Wear gloves when handling the spiny heads, then cut and dry them before threshing to collect seeds. Store seeds in airtight containers in a cool, dry place for both planting and medicinal use.