How to Grow Colvillei

iNaturalist

Colvillei

Ipomopsis aggregata

flower

Colvillei, also known as scarlet gilia, is a striking wildflower native to western North America with brilliant scarlet-red tubular flowers arranged in dense clusters. The plant typically grows 1-3 feet tall with delicate, feathery foliage and attracts hummingbirds and pollinators. It thrives in arid and semi-arid conditions, making it an excellent choice for dry gardens and xeriscape landscapes.

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

  1. Plant Colvillei

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Colvillei blooms

    Around Aug 15

    ≈ 120 days after planting

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

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; tolerates partial shade in hot climates
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Water: Low water needs once established; minimal watering required. Water moderately during establishment and growth. Drought tolerant; overwatering leads to root rot. Allow soil to dry between waterings.
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Spacing: 12 inches
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Days to maturity: 120-150 days from seed to flowering
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Planting depth: Surface sow or barely cover seeds; requires light to germinate

Soil

Type: Well-draining sandy or gravelly soil, tolerates poor soil
pH: 6.0-7.5
Amendments:
perlite or coarse sand for drainage gravel mulch to reduce moisture retention

Growing Zones

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Thrives in zones 3-9, tolerates zone 10 with afternoon shade

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

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Growth Stages

1

Germination

2-3 weeks

Seeds sprout with tiny cotyledons; light is critical for germination

Keep soil slightly moist but not wet; provide light exposure; germination occurs in 10-14 days at 60-70°F

2

Seedling

3-4 weeks

Develops first true leaves; forms delicate fern-like foliage; growth is slow initially

Provide bright indirect light; keep soil lightly moist; thin seedlings to appropriate spacing; avoid overwatering

3

Vegetative Growth

4-6 weeks

Plant grows taller with increasingly feathery foliage; develops woody base; gradually becomes more robust

Reduce watering as plant becomes established; no fertilizer needed in poor soil (plant actually prefers lean conditions); stake if needed in windy locations

4

Flowering

6-8 weeks

Dense clusters of brilliant scarlet-red tubular flowers appear at stem tips; flowers open progressively from bottom to top

Deadhead spent flowers to encourage continued blooming; ensure excellent drainage; water only during extended drought; enjoy hummingbird visits

5

Seed Production & Senescence

4-6 weeks until frost

Flowers fade; seed pods develop; plant begins to decline as energy goes into seed production

Allow flowers to remain on plant if collecting seeds; harvest seed pods before they fully dry and shatter; plant may self-sow if seeds reach soil

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Moisture-loving plants like hostas Ferns that prefer rich soil Plants requiring frequent watering like hydrangeas

Common Pests

  • Spray with water; use neem oil if severe; ensure adequate air circulation

  • Spray water jet to dislodge; use insecticidal soap; encourage natural predators like ladybugs

  • Yellow sticky traps; spray with neem oil or insecticidal soap; ensure good drainage to reduce stress

Uses

🍳

Hummingbird Nectar Source

Culinary

Colvillei's abundant tubular flowers are a primary nectar source for hummingbirds and other pollinators. The high nectar production makes it exceptionally valuable in wildlife gardens. [source]

🦋

Wildlife Garden Plantings

Wildlife

Widely used in native plant gardens and xeriscapes throughout the western United States to support hummingbirds, butterflies, and native bee populations. Creates dramatic focal points while supporting local ecosystems. [source]

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Drought-Tolerant Landscaping

Household

Ideal for water-wise gardens, rock gardens, and arid landscapes. Requires minimal maintenance once established and eliminates the need for supplemental irrigation in most climates. [source]

🎨

Ornamental Cut Flowers

Craft

Striking scarlet flowers can be cut for arrangements, though they are more valued in the garden for their ongoing display and pollinator attraction throughout the growing season. [source]

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Traditional Native Use

Medicinal

Historically used by Native American peoples in the southwestern United States for various medicinal purposes, though modern documentation is limited. Contains alkaloids of ethnobotanical 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

Allow flowers to bloom for garden display and hummingbird attraction. For seed collection, wait until seed pods dry and turn brown (late summer to early fall), then cut stems and collect seeds from open pods. Dry seeds further indoors and store in cool, dry conditions. Plant self-seeds readily if allowed.

Fun Facts

  • 🌱 Colvillei is named after the Colville family and exhibits remarkable adaptation to desert conditions, often flowering in the second year after seed production to ensure survival in arid environments.
  • 🌱 The brilliant red flowers are specially adapted to hummingbird vision and feeding behavior; hummingbirds are so attracted that they will visit Colvillei plantings multiple times daily during blooming season.
  • 🌱 In its native habitat, Colvillei often grows at elevations between 4,000-9,000 feet and frequently naturalizes in disturbed areas, roadsides, and dry washes throughout the western United States.

Gardening Terms

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

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