How to Grow Kermesina
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Kermesina
Ricinus communis 'Kermesina'
shrubKermesina is a striking ornamental cultivar of the castor bean plant, renowned for its deep red to burgundy foliage and dramatic appearance. This fast-growing shrub features large, deeply lobed leaves with a rich crimson color and impressive height, making it an excellent choice for tropical and subtropical gardens. The plant also produces distinctive seed pods and red flower spikes, adding to its visual appeal.
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Example Kermesina timeline · Pittsburgh, PA (Zone 6b)
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Plant Kermesina
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Kermesina
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Kermesina dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9b-11; can be grown as an annual in cooler zones 8-9
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Germination & Seedling
2-3 weeksSeeds sprout within 7-14 days; seedlings develop first true leaves with distinctive lobed shape and begin showing reddish tones.
Keep soil warm (70-80°F) and moist. Provide bright, indirect light. Thin seedlings to prevent crowding.
Vegetative Growth
4-6 weeksRapid expansion of large, deeply lobed leaves that develop intense burgundy-red coloration. Plant grows tall and bushy with strong stems.
Water regularly and maintain consistent moisture. Fertilize every 2-3 weeks with balanced fertilizer. Pinch back growing tips to encourage branching if desired.
Flowering
3-4 weeksRed flower spikes (inflorescences) emerge at branch tips; flowers are small and clustered in showy red panicles.
Continue regular watering and fertilizing. The red flowers complement the dark foliage beautifully.
Seed Pod Development
4-6 weeksDistinctive spiky seed pods develop from flowers, initially green then turning red to brown. Pods are covered in soft spines.
Monitor pods for maturity. Allow some to dry on plant for ornamental effect. Remove pods before they burst if self-seeding is not desired.
Mature Plant
Ongoing throughout seasonFully developed shrub with dense foliage, dramatic red coloration, visible seed pods, and impressive height (6-12 feet depending on conditions).
Maintain watering schedule. Prune to maintain shape and size. Protect from harsh winds. In cooler climates, treat as annual or bring indoors.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with neem oil or insecticidal soap; increase humidity; remove heavily infested leaves
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Use yellow sticky traps; spray with neem oil or insecticidal soap; encourage beneficial insects
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Remove with cotton swab dipped in rubbing alcohol; spray with neem oil; isolate infested plants
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Prune affected branches; spray with horticultural oil; scrape off manually
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Remove affected leaves; improve air circulation; avoid overhead watering; apply fungicide if severe
Uses
Ornamental Foliage Display
HouseholdThe striking deep burgundy-red foliage creates dramatic focal points in gardens, containers, and landscape designs. The color intensifies in full sun and provides year-round visual interest in tropical climates. [source]
Dried Arrangements & Floral Design
CraftThe decorative seed pods can be dried and used in floral arrangements, wreaths, and craft projects. The spiky texture and rich coloring add visual interest to dried botanicals. [source]
Pollinator Attraction
WildlifeThe bright red flower spikes attract hummingbirds, bees, and other pollinators. The plant provides nectar and creates a vibrant garden ecosystem. [source]
Traditional Medicine (Non-Culinary)
MedicinalIn traditional medicine systems, castor plants have been used for various remedies, though Kermesina is more valued ornamentally. Use only under professional guidance—the plant contains toxic compounds. [source]
Tropical Garden Specimen Plant
HouseholdPerfect as a dramatic specimen plant or background element in tropical and subtropical gardens, adding height, color, and architectural interest. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Kermesina is primarily grown for ornamental foliage and flowers rather than harvest. Allow seed pods to mature on the plant for visual appeal. If harvesting seeds (use gloves—seeds are toxic), wait until pods dry and brown, then carefully collect. Never harvest for consumption; all parts are toxic.
Fun Facts
- 🌱 Kermesina's deep red color comes from anthocyanin pigments, the same compounds that color red wine and blueberries—though Kermesina's are purely ornamental and never edible.
- 🌱 The castor bean plant (Ricinus communis) is the source of castor oil, a valuable commercial product, but the Kermesina cultivar is grown specifically for its dramatic ornamental value rather than oil production.
- 🌱 In frost-prone areas, Kermesina grows incredibly fast as an annual, often reaching 4-6 feet in a single season, making it a quick way to add dramatic height and color to a garden.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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