How to Grow Firespike

Firespike

Odontonema cuspidatum

shrub

Firespike is a tropical to subtropical evergreen shrub known for its striking tubular flowers that bloom in vibrant red, orange, or scarlet clusters. Native to Mexico, it attracts hummingbirds and butterflies with its nectar-rich blooms that appear from mid-summer through fall. This ornamental plant thrives in warm climates and adds dramatic color to gardens and landscapes.

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Example Firespike timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Firespike

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Firespike

    Around Jul 16

    ≈ 90 days after planting

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

Growing Conditions

☀️
Sun: Full sun to partial shade; 6-8 hours of direct sunlight daily for best flowering
💧
Water: Keep soil consistently moist but not waterlogged during the growing season. Water deeply and regularly, especially during hot, dry periods. Reduce watering in winter. Drought-tolerant once established but flowers best with regular moisture.
📏
Spacing: 36 inches
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Days to maturity: 90-120 days to first flowers from planting
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Planting depth: Plant at same depth as nursery container; transplants should have top of root ball level with soil surface

Soil

Type: Well-draining, fertile loamy soil
pH: 6.0-7.0
Amendments:
Compost or aged manure for enrichment Perlite or sand for drainage improvement Mulch to retain moisture and regulate temperature

Growing Zones

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

9b 10a 10b 11a 11b

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Growth Stages

1

Establishment

4-8 weeks

Young plants are leafy green shrubs with soft stems and dark green, lance-shaped leaves

Water regularly to establish deep roots. Provide afternoon shade in hot climates. Protect from strong winds. Apply mulch around base.

2

Vegetative Growth

6-10 weeks

Plant develops woody stems and fuller foliage; becomes more compact and bushy

Pinch back growing tips to encourage branching and denser growth. Fertilize every 2-3 weeks with balanced fertilizer. Continue regular watering.

3

Bud Formation

2-4 weeks

Terminal spikes develop small red or orange buds at branch tips

Maintain consistent moisture and fertilizer schedule. Avoid over-fertilizing with nitrogen as it reduces flowering. Ensure adequate sunlight.

4

Flowering

8-12 weeks

Showy tubular flowers in red, orange, or scarlet colors open sequentially on dense spikes, attracting hummingbirds

Continue regular watering and feeding with lower-nitrogen, higher-phosphorus fertilizer to promote more blooms. Deadhead spent flowers to encourage continued flowering.

5

Dormancy/Decline

3-4 months

Flowering slows in late fall and winter; plant may lose some leaves in cold snaps or very dry conditions

Reduce watering and fertilizer. Prune out dead or frost-damaged wood. In zones below 9b, bring container plants indoors or protect with frost cloth.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Walnut trees (juglone toxicity) Eucalyptus (allelopathic effects)

Common Pests

  • Spray with water to dislodge; use neem oil or insecticidal soap if severe. Increase humidity.

  • Use yellow sticky traps; spray with neem oil or insecticidal soap. Remove heavily infested leaves.

  • Prune out heavily infested branches; spray with horticultural oil or neem oil. Monitor regularly.

  • Remove with rubbing alcohol on a cotton swab; spray with neem oil or insecticidal soap for large infestations.

  • Spray forcefully with water; use insecticidal soap or neem oil. Encourage beneficial insects like ladybugs.

Uses

🍳

Hummingbird Nectar

Culinary

While not directly consumed by humans, firespike flowers produce nectar that attracts hummingbirds and other pollinators, supporting biodiversity in the garden. [source]

🏠

Cut Flowers & Arrangements

Household

The vibrant red or orange flower spikes make striking cut flowers for floral arrangements and can last up to a week in water. [source]

🦋

Pollinator Support

Wildlife

Firespike is an excellent nectar source for hummingbirds, butterflies, and other beneficial insects, making it valuable for wildlife gardens and pollinator corridors. [source]

🎨

Ornamental Landscaping

Craft

The shrub's dramatic tubular flowers and evergreen foliage make it a popular choice for tropical and subtropical garden design, accent plantings, and container gardening. [source]

💊

Traditional Herbal Use

Medicinal

In traditional Mexican herbalism, Odontonema species have been used for various medicinal purposes, though scientific validation is limited. [source]

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

Harvest Tips

Firespike is an ornamental shrub, not harvested for fruit or vegetables. However, you can cut flowers for arrangements when tubular blooms are fully open. Cut stems in early morning for longest vase life (typically 5-7 days). Regular deadheading of spent flowers encourages continued blooming throughout the season.

Fun Facts

  • 🌱 Firespike's tubular flowers are specifically adapted for hummingbird pollination, with their long, narrow shape perfectly matching the shape of a hummingbird's beak.
  • 🌱 The plant is also called Scarlet Sage in some regions, though it is not related to true sages; it belongs to the Acanthaceae (Acanthus) family.
  • 🌱 In tropical regions where it thrives year-round, firespike can bloom almost continuously if provided with consistent water and fertilizer.

Gardening Terms

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

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