How to Grow Flame Spike

Flame Spike

Odontonema cuspidatum

shrub

Flame Spike is a tropical shrub prized for its brilliant red-orange tubular flowers that bloom in dense spikes from mid-summer through fall. Native to Mexico, it grows as an evergreen perennial in warm climates and reaches 3-6 feet tall, attracting hummingbirds and butterflies. The dark green, lance-shaped foliage provides an attractive backdrop to the vibrant flower displays.

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Example Flame Spike timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Flame Spike

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Flame Spike

    Around Jul 16

    ≈ 90 days after planting

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

Growing Conditions

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Sun: Full sun to partial shade; 6-8 hours of direct sunlight daily for best flowering
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Water: Keep soil consistently moist but not waterlogged during growing season. Reduce watering in winter. Tolerates moderate drought once established but performs best with regular watering.
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Spacing: 36 inches
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Days to maturity: 90-120 days to first blooms from transplant
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Planting depth: Same depth as nursery pot; do not bury stem deeper than soil line

Soil

Type: Well-draining, fertile loamy soil
pH: 6.0-6.8
Amendments:
Compost Peat moss Perlite for drainage

Growing Zones

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Thrives in zones 9b-11; can be grown in containers and brought indoors in cooler zones

9b 10a 10b 11a 11b

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Growth Stages

1

Establishment

3-4 weeks

Young transplant with limited branching and dark green foliage establishing root system

Water regularly to keep soil moist. Protect from strong winds. Avoid fertilizing immediately; allow roots to establish for 2-3 weeks.

2

Vegetative Growth

4-6 weeks

Plant develops multiple stems and fuller branching structure; foliage expands significantly

Pinch back shoot tips to encourage bushier growth. Fertilize monthly with balanced fertilizer. Remove any weak or damaged branches.

3

Pre-flowering

2-3 weeks

Stem tips thicken and buds begin forming at branch ends; leaves may appear slightly narrower

Maintain consistent moisture and warmth (above 60°F). Continue fertilizing with bloom-promoting formula (higher phosphorus). Reduce nitrogen to encourage flowering.

4

Flowering

6-12 weeks

Dense spikes of tubular red-orange flowers emerge and open sequentially along stems; peak color display

Continue watering regularly; flowers develop best with consistent moisture. Deadhead spent flowers to encourage continued blooming. Provide afternoon shade in hottest climates (above 95°F).

5

Dormancy/Winter

3-4 months

Flower production slows or stops; growth becomes minimal. Foliage may yellow slightly in cool temperatures.

Reduce watering frequency significantly. In zones below 10, bring containers indoors or mulch heavily. Minimal fertilizing needed. Prune lightly in late winter to shape plant.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black Walnut (Juglans nigra) Eucalyptus

Common Pests

  • Spray with insecticidal soap or neem oil every 7-10 days. Encourage natural predators like ladybugs. Remove heavily infested leaves.

  • Increase humidity by misting foliage. Apply miticide or neem oil spray. Wash leaves with strong water spray to dislodge mites.

  • Spray with insecticidal soap or horticultural oil. Remove affected areas with pruning. Apply systemic insecticide if severe.

  • Prune out heavily infested branches. Spray with horticultural oil during dormant season. Apply insecticidal soap to stems and leaves.

Uses

🦋

Hummingbird and Butterfly Magnet

Wildlife

The tubular red-orange flowers are a prime nectar source for hummingbirds, ruby-throated hummingbirds especially, and attract numerous butterfly species. Blooming continuously from mid-summer through frost makes it essential for late-season pollinator support. [source]

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Cut Flower Arrangements

Household

The striking flower spikes make excellent long-lasting cut flowers for tropical and warm-climate floral arrangements. Harvest spikes in the morning when fully hydrated for maximum vase life of 5-7 days. [source]

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Edible Flowers

Culinary

The tubular flowers are edible and can garnish tropical cocktails and desserts, offering visual appeal and a mild, slightly sweet flavor. Ensure no pesticides have been applied before consuming. [source]

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Tropical Landscape Accent

Household

Flame Spike's vibrant color and upright growth habit make it a dramatic focal point in tropical and subtropical gardens. Use as a specimen plant, in mixed borders, or in containers on patios and porches. [source]

💊

Traditional Herbal Use

Medicinal

In its native Mexico and Central America, Flame Spike has been used in traditional herbalism, though scientific research is limited. Some sources suggest mild anti-inflammatory properties in leaf preparations. [source]

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

Harvest Tips

Flame Spike is ornamental; no harvest in traditional sense. Cut flowers last 5-7 days in a vase with fresh water. Prune stems in late winter before new growth to maintain shape and size. Cut stems at 45-degree angle just above a leaf node.

Fun Facts

  • 🌱 Flame Spike was previously classified under the genus Jacobinia and is still sometimes sold under that name in nurseries.
  • 🌱 The plant's genus name 'Odontonema' comes from Greek words meaning 'tooth' and 'thread,' referring to the appearance of the flowers' reproductive structures.
  • 🌱 Hummingbirds can visit Flame Spike flowers dozens of times per day during peak blooming season, making it one of the most valuable plants for these birds in warm regions.

Gardening Terms

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