🌸 Milk Thistle: Growing Guide
Milk Thistle (Silybum marianum) grows best in full sun with little water, and does well at −15 to 38 °C (5–100 °F) in soil with a pH of 5.5–7.5. Space plants about 60 cm (24 in) apart. Expect 120+ days (a perennial — it takes more than a season).
Quick facts
| Scientific name | Silybum marianum |
|---|---|
| Category | Medicinal |
| Sunlight | Full sun |
| Watering | Low |
| Plant spacing | 60 cm (24 in) |
| Soil pH | 5.5–7.5 |
| Comfortable temperature | −15 to 38 °C (5–100 °F) |
| Time to maturity | 120+ days (a perennial — it takes more than a season) |
| Sowing depth | 0.5 cm (0.2 in) |
| Height | 100–200 cm (39–79 in) |
When to sow, plant and harvest
The calendar below shows the best months in each climate zone. Pick the zone closest to your garden.
| J | F | M | A | M | J | J | A | S | O | N | D | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mediterranean | Sow | Plant out | Harvest | Harvest | ||||||||
| Continental | Sow | Plant out | Harvest | Harvest | ||||||||
| Oceanic | Sow | Plant out | Harvest | Harvest | ||||||||
| Subtropical | Sow | Plant out | Harvest | Harvest | Sow | Harvest | ||||||
| Tropical | Sow | Plant out | Harvest | Harvest | Sow | Harvest | ||||||
| Cold / Northern | Sow | Plant out | Harvest | |||||||||
| Arid / Semi-arid | Sow | Plant out | Harvest | Harvest |
- Mediterranean (Greece, Spain, Italy, coastal Turkey): Sow: Mar · Plant out: Apr · Harvest: May–Jun.
- Continental (Central/Northern Europe, inland Balkans): Sow: Apr · Plant out: May · Harvest: Jun–Jul.
- Oceanic (UK, France, Belgium, Netherlands, NW Europe): Sow: Mar · Plant out: Apr · Harvest: May–Jun.
- Subtropical (Southern US, N. Africa, Middle East): Sow: Jan, Aug · Plant out: Feb · Harvest: Mar–Apr, Sep.
- Tropical (SE Asia, Sub-Saharan Africa, Amazon): Sow: Jan, Jul · Plant out: Feb · Harvest: Mar–Apr, Aug.
- Cold / Northern (Scandinavia, Canada, Russia, Alpine): Sow: May · Plant out: Jun · Harvest: Jul.
- Arid / Semi-arid (Arabian Peninsula, inland Australia): Sow: Feb · Plant out: Mar · Harvest: Apr–May.
Watering
Water about every 5 days in summer and about every 14 days in winter. Drought tolerant.
Growing tips
Contains silymarin. Common in the countryside. Purple flowers. Young leaves are edible.
Good companion plants
These plants grow well alongside it:
Frequently asked questions
Milk Thistle: when should I sow and plant it?
Mediterranean (Greece, Spain, Italy, coastal Turkey): Sow: Mar · Plant out: Apr · Harvest: May–Jun. Continental (Central/Northern Europe, inland Balkans): Sow: Apr · Plant out: May · Harvest: Jun–Jul. Oceanic (UK, France, Belgium, Netherlands, NW Europe): Sow: Mar · Plant out: Apr · Harvest: May–Jun.
Milk Thistle: how often should I water it?
Water about every 5 days in summer and about every 14 days in winter. Drought tolerant.
Milk Thistle: how far apart should I plant it?
Plant about 60 cm (24 in) apart and sow at a depth of about 0.5 cm (0.2 in).
Milk Thistle: how long does it take to grow?
Plan on 120+ days (a perennial — it takes more than a season).
Milk Thistle: which plants grow well with it?
Oregano.
Plan your garden
Add Milk Thistle to your garden design in the free GardenXPro planner: drag plants onto a 2D plan, preview it in 3D, check companions and get watering reminders.
Open the free planner →