Calabar bean Plant Care
Physostigma venenosum Balf.
Updated · Sources · How we source care data
This plant is recognized by its large, glossy green leaves with a unique texture resembling wrinkled paper. Originating from tropical Africa, Physostigma venenosum is highly sought after by plant collectors for its striking foliage and historical medicinal uses as a source of the toxic alkaloid physostigmine.
Every 7–14 days
Bright indirect light
65–85°F
60–80%
At a glance
How do you care for Calabar bean?
Water Calabar bean every 7–14 days, letting the top layer of soil dry out between waterings, and give it bright indirect light. It prefers temperatures of 65–85°F (18–29°C) and 60–80% humidity. Fertilize it every month during the growing season. It is reported as toxic to pets, so keep it out of reach of pets.
Where Is the Calabar bean Native To?
- Angola
- Benin
- Burkina Faso
- Burundi
- Cameroon
- Cape Verde
- Central African Republic
- Chad
- Côte d'Ivoire
- Djibouti
- DR Congo
- Equatorial Guinea
- Eritrea
- Ethiopia
- Gabon
- Ghana
- Guinea
- Guinea-Bissau
- Kenya
- Liberia
- Malawi
- Mali
- Mauritania
- Mozambique
- Niger
- Nigeria
- Republic of the Congo
- Rwanda
- Sao Tome and Principe
- Senegal
- Sierra Leone
- Somalia
- South Sudan
- Sudan
- Tanzania
- The Gambia
- Togo
- Uganda
- Zambia
- Zimbabwe
What Is the Calabar bean?
Calabar bean (Physostigma venenosum) belongs to the Fabaceae family within the Physostigma genus. Calabar bean is native to tropical Africa, with a seed poisonous to humans. Calabar bean is also known as Ordeal bean.
Calabar bean displays a twining vine growth habit, reaching up to 10 ft tall with a spread of approximately 6 ft. Calabar bean produces showy, tubular flowers in shades of purple and white.
Leaf size: approximately 8 inches.
How Often Should You Water a Calabar bean?
Physostigma venenosum requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–14 days
Let soil partially dry between waterings
What Light Does the Calabar bean Need?
Calabar bean thrives in bright indirect light. Avoid placing Calabar bean in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Bright indirect light
What Temperature and Humidity Does the Calabar bean Prefer?
Physostigma venenosum grows best at temperatures of 65–85°F. Calabar bean prefers humidity levels of 60–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
65–85°F
Humidity
60–80%
What Soil Mix Works Best for a Calabar bean?
Well-draining loamy soil mix with added organic matter for moisture retention. Good drainage is essential for Calabar bean to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Calabar bean?
Feed Calabar bean every month during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every month
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Calabar bean?
Repot every 1-2 years in spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Calabar bean?
Calabar bean can be propagated through seeds.
Is the Calabar bean Toxic to Pets and Children?
Toxic (caution)
Reported as toxic in our plant data. Not verified by the ASPCA.
Toxic to humans and pets
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Calabar bean?
Calabar bean is susceptible to aphids, spider mites, whiteflies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Calabar bean Need?
Calabar bean grows outdoors in USDA Zone 11a – 12b. It survives winters down to planting zone 11a. Calabar bean is native to tropical Africa, with a seed poisonous to humans. In cooler regions, grow Calabar bean as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 11a – 12b
Keep exploring plants
Calabar bean is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Physostigma genus — compare its care with other Physostigma species on PlantoScan.
Physostigma is part of the Fabaceae plant family — browse all Fabaceae genera and species.
Calabar bean thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Physostigma venenosum Balf., family Fabaceae (first published in Trans. Roy. Soc. Edinburgh 22: 310 (1861)) — World Flora Online record, IPNI name record.
- Pet toxicity: Calabar bean is reported as toxic to pets in our plant data (not verified by the ASPCA), so treat it with caution. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Hardiness zone: USDA Zone 11a – 12b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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