How to Grow Slender dayflower

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Slender dayflower

Commelinella dianthoidea

flower

Commelinella dianthoidea is a delicate, low-growing flowering plant in the Commelinaceae family, native to Mexico and Central America. It produces small, bright blue flowers that typically open in the morning and close by afternoon. This tender perennial is prized for its ornamental foliage and charming blooms in container and garden settings.

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Example Slender dayflower timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Slender dayflower

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Slender dayflower blooms

    Around Jun 16

    ≈ 60 days after planting

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

Growing Conditions

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Sun: Partial shade to dappled sunlight; 3-4 hours of indirect light daily. Tolerates shade better than intense afternoon sun.
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Water: Keep soil consistently moist but not waterlogged. Prefers humidity; water more frequently during growing season and reduce in winter dormancy.
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Spacing: 12 inches
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Days to maturity: 60-90 days to first flowers
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Planting depth: Seeds: surface sow or barely cover (1/8 inch). Transplants: plant at same depth as original pot.

Soil

Type: Well-draining, fertile loamy soil with organic matter
pH: 6.0-7.0
Amendments:
Compost or aged bark Perlite for drainage Peat moss or coco coir for moisture retention

Growing Zones

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Thrives in zones 10-11; grown as an annual or houseplant in cooler zones

10a 10b 11a 11b

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Growth Stages

1

Seedling

3-4 weeks

Tiny, delicate leaves emerge; very slow initial growth. Plant appears fragile with 2-4 true leaves.

Maintain high humidity (60-80%), provide bottom heat (70-75°F), use grow lights if indoors. Keep soil consistently moist. Avoid direct sun.

2

Vegetative growth

4-8 weeks

Plant develops creeping or mounding stems with lance-shaped, thin leaves. Foliage becomes fuller and more ornamental.

Pinch back growing tips to encourage branching and fuller shape. Maintain consistent moisture and humidity. Begin fertilizing every 2-3 weeks with dilute, balanced fertilizer.

3

Pre-flowering

2-3 weeks

Stems elongate slightly, foliage density increases, flower buds begin to form at stem tips.

Continue regular fertilizing, preferring slightly higher phosphorus to promote blooming. Ensure adequate indirect light. Maintain humidity and steady moisture.

4

Flowering

8-16 weeks or longer indoors

Delicate, typically blue (occasionally pink or white) ephemeral flowers open in morning, close by afternoon. Continuous blooming occurs over weeks to months.

Deadhead spent flowers to extend blooming. Maintain consistent care regimen. Reduce nitrogen slightly to avoid excessive foliage at expense of flowers.

5

Dormancy/rest

2-4 months

Growth slows significantly in cooler months or with reduced light. Foliage may yellow; plant becomes semi-dormant.

Reduce watering frequency. Lower fertilization or stop entirely. Provide cooler temperatures (50-60°F). Maintain humidity with occasional misting. Prune back dead material.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Drought-tolerant succulents Aglaonema Sansevieria Xerophytic ferns

Common Pests

  • Increase humidity through misting and grouping plants. Spray with water or insecticidal soap weekly if infested. Neem oil effective in severe cases.

  • Remove with rubbing alcohol on a cotton swab. Spray with insecticidal soap or neem oil every 7-10 days.

  • Ensure excellent drainage and avoid overwatering. Remove affected roots and repot in fresh soil. Improve air circulation.

  • Spray forcefully with water to dislodge. Use insecticidal soap or horticultural oil if needed.

Uses

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Indoor houseplant

Ornamental

Commelinella dianthoidea makes an excellent choice for bright bathrooms, vivariums, and terrariums where its love of humidity and moist soil can be accommodated. Its delicate trailing or creeping habit suits hanging baskets and shelf displays. [source]

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Tropical container gardens

Ornamental

Thrives in mixed container plantings with other shade-loving, humidity-preferring plants. Ideal for tropical-themed gardens and shade borders in warm climates. [source]

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Pollinator support

Wildlife

Though small and delicate, the flowers attract bees and other small pollinators. Provides a nectar source in humid, shaded garden areas. [source]

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Botanical propagation hobby

Craft

Easy to propagate from stem cuttings, making it a rewarding project for plant enthusiasts interested in plant propagation techniques and tissue culture. [source]

Harvest Tips

Not typically harvested as this is an ornamental flower. Simply enjoy the blooms as they open daily. Deadhead spent flowers to encourage continued blooming. Collect seeds if desired once flower develops small seed capsules.

Fun Facts

  • 🌱 Commelinella dianthoidea belongs to the Commelinaceae family, known for their ephemeral (short-lived) flowers that bloom for a single day—hence the common name 'dayflower.' The flowers close permanently by afternoon.
  • 🌱 This plant is sometimes called the 'inch plant' relative to its slow, creeping growth habit when used as a groundcover, though true 'inch plants' (Tradescantia zebrina) are more vigorous.
  • 🌱 The genus Commelinella was named in honor of the Commelin brothers, Dutch botanists and naturalists from the 17th century.

Gardening Terms

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

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