How to Grow Combretum grandiflorum

Combretum grandiflorum

vine

Combretum grandiflorum, commonly known as Scarlet Hoya or Flame Vine, is a tropical climbing vine native to West Africa. It produces stunning clusters of deep red-scarlet flowers that bloom year-round in warm climates. This vigorous vine is prized for its showy, tubular blooms and is excellent for trellises, arbors, and as a container specimen in cooler regions.

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Example Combretum grandiflorum timeline · Pittsburgh, PA (Zone 6b)

Plant Combretum grandiflorum
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
Harvest Combretum grandiflorum
Late summer into fall

Before the first fall frost (≈ Nov 8)

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Growing Conditions

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Sun: Full sun to bright indirect light, 6-8 hours of direct sunlight daily for best flowering

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Water: Keep soil consistently moist during growing season, but not waterlogged. Water deeply when top inch of soil is dry. Reduce watering in winter. High humidity (50-70%) promotes vigorous growth and blooming.

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Spacing: 12 inches

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Days to maturity: 180-365 (blooms can appear within 6-12 months with mature plants; this is an ongoing vine)

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Planting depth: Same depth as root ball for transplants; seeds planted 1/4 inch deep

Soil

Type: Well-draining loamy soil with organic matter

pH: 6.0-7.0

Amendments:

Compost or aged bark Perlite for drainage Orchid bark (for container growing)

Growing Zones

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Thrives in USDA zones 11-12; can be grown in zone 10b with protection; elsewhere as a container plant brought indoors

11a 11b 12a 12b

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Growth Stages

Seedling

4-8 weeks

Tiny plants with 2-4 true leaves, fragile and delicate

Maintain high humidity and consistent moisture. Use bottom heat (70-75°F) to encourage germination. Keep under bright indirect light. Provide gentle airflow to prevent damping off.

Vegetative Growth

3-12 months

Rapid stem and leaf development; no flowers yet. Vine grows vigorously with increasingly larger compound leaves

Provide sturdy support structure or trellis early. Fertilize every 2-3 weeks with balanced NPK fertilizer. Pinch tips regularly to encourage bushier, fuller growth. Maintain warm temperatures (70-85°F).

Flowering (Bud Formation)

2-4 weeks before blooms open

Flower buds form at branch tips; clusters of deep red buds appear before opening

Reduce nitrogen slightly to encourage blooming over leaf growth. Maintain consistent moisture and humidity. Ensure 6-8 hours of direct sunlight daily. Avoid moving the plant during bud formation.

Full Bloom

4-12 weeks (can bloom multiple times yearly)

Dense clusters of tubular scarlet flowers fully open, displaying brilliant red color. Multiple blooms appear along the vine

Continue regular watering and maintain humidity. Fertilize every 2-3 weeks with bloom-boosting formula (higher phosphorus). Deadhead spent flowers to extend blooming period. Provide full sun for brightest color.

Post-Bloom & Pruning

2-4 weeks

Flowers fade and drop; plant may rest briefly before new blooms appear

Light pruning to remove spent flower clusters and shape the vine. Clean up fallen petals. In cooler climates, allow plant to rest for 4-6 weeks with reduced watering before forcing new growth.

Companion Planting

Plan your garden →

Plant with:

Mandevilla Clematis Bougainvillea Passiflora Thunbergia

Avoid planting near:

Plants requiring dry conditions Cacti Drought-tolerant succulents

Common Pests

Increase humidity with regular misting. Spray with neem oil or insecticidal soap weekly. Rinse leaves with water to dislodge mites. Isolate infected plants.
Remove with cotton swab dipped in rubbing alcohol. Spray with insecticidal soap or neem oil every 7-10 days. Prune heavily infested stems. Improve air circulation.
Scrape off manually with soft brush or cloth. Apply horticultural oil or neem oil spray. Treat every 7-14 days until resolved. Remove severely infested branches.
Use yellow sticky traps. Spray with insecticidal soap or neem oil. Increase air circulation with fans. Isolate affected plants.
Improve air circulation and reduce humidity slightly. Spray with sulfur dust or potassium bicarbonate. Remove affected leaves. Avoid overhead watering.

Uses

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Ornamental use only

Culinary

Combretum grandiflorum is not edible and not used in culinary applications. The plant is strictly ornamental. [source]

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Garden ornament and landscaping

Household

The vine is prized for covering arbors, pergolas, trellises, and fences with brilliant scarlet flowers. It creates dramatic focal points in tropical and subtropical gardens and adds vertical interest to outdoor spaces. [source]

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Container and indoor plant

Household

In cooler climates, Combretum grandiflorum thrives as a houseplant near bright windows or under grow lights. The vining habit allows it to be trained on moss poles or trellises indoors, making it suitable for conservatories and bright atriums. [source]

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Traditional African medicine

Medicinal

In West African traditional medicine, various Combretum species, including C. grandiflorum, have been used in traditional remedies, though scientific validation is limited. Always consult healthcare providers before medicinal use. [source]

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Pollinator attraction

Wildlife

The tubular scarlet flowers are highly attractive to hummingbirds, sunbirds, and long-tongued insects in tropical regions. The abundant nectar makes it an excellent choice for pollinator-friendly gardens. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Combretum grandiflorum is an ornamental plant grown for flowers, not harvested for food or material. Cut flowers can be harvested by snipping stems with sharp pruners in early morning when fully open. Flowers last 1-2 weeks in fresh arrangements. For propagation, take semi-hardwood cuttings (4-6 inches) in spring/summer, treat with rooting hormone, and root in moist propagation medium under humidity. Seeds can be collected from spent flower clusters but germination rates are variable.

Fun Facts

🌱 Combretum grandiflorum is native to West Africa, particularly countries like Ghana and Côte d'Ivoire, where it grows as a wild climbing vine in tropical forests.
🌱 The plant produces abundant, tubular scarlet flowers year-round in ideal warm conditions, with some plants blooming multiple times per year, making it one of the longest-blooming tropical vines.
🌱 Seeds of Combretum species are winged (samaroid fruits) that disperse by wind, allowing the plant to spread through tropical forest canopies in its native habitat.

Gardening Terms

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

Damping Off Deadhead Full Sun Germination pH Trellis True Leaves

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