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Ricinus

Ricinus communis
Also known as: Castor Bean

Ricinus is a flower in the Euphorbiaceae family. It grows best in full sun with medium moisture, and is listed for USDA zones 2-13. Plants reach maturity about 100–140 days after planting and sit about 12 inches apart.

Varieties

1 from True Leaf Market · sorted by days to maturity
  • ▸Castor Bean100–140 days

    Non-GMO; Annual

    56-63 Days to maturity. Ricinus communis. Castor Bean Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Castor Bean seeds grow one of the tallest, and most notorious blooms in the world! Ricinus seeds promise an unbelievable plant ideal for a shrubby border in the back of the garden or just sown wildly. Castor Bean is easy to grow from seed and is one of the most resilient and fastest-growing plants in all of North America with large palmate leaves. Ricinus is infamously toxic if ingested, and verified by the Guinness Book of World Records as being the world's most poisonous houseplant. Approximately 70 Seeds / Ounce.

    View on True Leaf Market ↗
Family
Euphorbiaceae
Category
Flower
Form
Bush
Lifecycle
annual
Zone
2-13
Height
6–10 ft
Spread
3–4 ft
Sun
Full sun

Plant spacing

1 plant per square footSquare-foot planting diagram: one ricinus fills a 1-foot square, spaced 12 inches from its neighbors.
1 plant per square foot

In a square-foot bed, space ricinus about 12 in apart — that fits 1 plant in each 1-foot square (1×1). Wider rows or containers space the same.

Water
Medium

Plan your ricinus planting

Add ricinus to a free GardenDraft plan and get sow, transplant, and harvest dates computed for your ZIP code — with a drag-and-drop bed layout and reminders when it’s time to plant.

Start your free plan →

At a glance

Days to harvest
100–140 days
From transplant or sow to first harvest
Harvest style
Harvest once
One main harvest
After harvest
Use within days
Quality eases off after peak
Frost tolerance
Tender · to ~32°F
Lowest temperature the foliage usually survives
Germination
~65%
Typical minimum germination rate

Growing timeline

When to plant and harvest ricinusPlanting timeline for ricinus, relative to last frost: start indoors from 7 weeks before last frost to 1 week after last frost; grow from 1 week after last frost to 15 weeks after last frost; harvest from 15 weeks after last frost to 21 weeks after last frost.Start indoorsGrowHarvestLast frostTransplant
Start ricinus indoors ~8 weeks before transplanting 1 week after last frost; first harvest 15 weeks after last frost.
Seed to transplant
42-56 days
Outdoor planting
7 to 14 days vs frost
Propagation
Seed
Schedule anchor
Last Frost

Care & troubleshooting

No curated care & troubleshooting advice for ricinus yet. Our extension-sourced library currently focuses on common edible crops; we're expanding it over time.