How to Grow Smithiantha cinnabar

iNaturalist

Smithiantha cinnabar

flower

Smithiantha cinnabar is a stunning tropical houseplant belonging to the Gesneriaceae family, known for its vibrant cinnabar-red tubular flowers that bloom in terminal racemes. The plant features attractive, velvety, dark green foliage with deep red veining and fuzzy stems. It is an excellent choice for indoor gardeners seeking a showy, relatively low-maintenance flowering plant.

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Example Smithiantha cinnabar timeline · Pittsburgh, PA (Zone 6b)

Plant Smithiantha cinnabar
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
First Smithiantha cinnabar blooms
Around Jul 16

≈ 90 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Smithiantha cinnabar dates for your own zip code.

Growing Conditions

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Sun: Bright, indirect light; 12-14 hours daily ideal for flowering

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Water: Keep soil consistently moist but not waterlogged during growing season; reduce watering significantly after blooming; avoid wetting foliage to prevent fungal issues

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Spacing: 8 inches

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Days to maturity: 90-120 days from tuber sprouting to first blooms

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Planting depth: Plant tubers 0.5 inches below soil surface

Soil

Type: Well-draining, light, humus-rich soil

pH: 6.0-6.8

Amendments:

Perlite or coarse sand Peat moss or coco coir Orchid bark Compost

Growing Zones

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Zones 10b-11 outdoors; grown as a houseplant in cooler climates

10b 11a 11b

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Growth Stages

Dormancy

October-January

Rhizomatous tubers are dormant; leafless and underground

Store tubers in cool, dry location (50-60°F); check occasionally for mold; minimal watering

Sprouting & Vegetative Growth

4-6 weeks

New shoots emerge from tubers; fuzzy stems and velvety foliage develop rapidly

Plant tubers in prepared soil; maintain warm temperatures (65-75°F); provide bright indirect light; keep soil consistently moist

Leafing Out

3-4 weeks

Plant develops full canopy of deep green, velvety leaves with prominent red veining

Maintain humidity (50-70%); fertilize every 2-3 weeks with diluted balanced or high-phosphorus fertilizer; ensure good air circulation

Flowering

6-10 weeks

Tall flower spikes emerge with tubular cinnabar-red flowers opening progressively from bottom to top

Maintain consistent bright indirect light and temperatures; continue regular watering and feeding; remove spent flowers to encourage blooming

Senescence & Dormancy

4-6 weeks

Foliage yellows and dies back naturally; flowers fade

Gradually reduce watering as plant declines; allow foliage to die back completely; move to cool location; tubers enter dormancy

Companion Planting

Plan your garden →

Plant with:

Streptocarpus Gloxinia Columnea Episcia African violet

Avoid planting near:

Drafty locations Direct heat sources Plants requiring low humidity

Common Pests

Isolate plant; spray with insecticidal soap or neem oil; wipe leaves with alcohol-soaked cotton swabs
Use yellow sticky traps; spray with neem oil or insecticidal soap; improve air circulation
Increase humidity; spray with water or miticide; remove severely infested leaves
Allow soil to dry slightly between waterings; use mosquito dunks; use yellow sticky traps

Uses

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Indoor Ornamental Display

Household

Smithiantha cinnabar serves as a spectacular indoor flowering houseplant, bringing tropical elegance to homes and conservatories. Its dramatic cinnabar-red flower spikes provide months of vibrant color and visual interest. [source]

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Cut Flower Arrangements

Craft

The tall, striking flower spikes of Smithiantha cinnabar are excellent for fresh cut flower arrangements and tropical-themed floral designs. They maintain color and form for several weeks when properly conditioned. [source]

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Shade Plant for Conservatories

Household

Its preference for bright indirect light makes Smithiantha ideal for interior conservatories, terrariums, and shade houses where it adds exotic color without requiring full sun. It thrives under artificial grow lights. [source]

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Pollinator Attraction

Wildlife

The tubular red flowers of Smithiantha attract hummingbirds and other pollinators, making it valuable for creating wildlife-friendly indoor or patio gardens in warm climates. [source]

Harvest Tips

Smithiantha is ornamental and not harvested; flowers can be enjoyed on the plant for 6-10 weeks and are long-lasting. For floral arrangements, cut flower spikes in the morning when several flowers have already opened, placing them immediately in water.

Fun Facts

🌱 Smithiantha is named after the Smithe family, early horticulturists; the genus was established by botanist Lew Lenz and has become popular in tropical houseplant collecting.
🌱 The velvety texture of Smithiantha foliage is due to fine hairs that help reduce water loss and aid in the plant's epiphytic heritage—it naturally grows on trees in cloud forests.
🌱 Smithiantha species have become increasingly popular among Gesneriad enthusiasts, with hybridization efforts creating new color forms beyond the classic cinnabar red.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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