How to Grow Commelina

Commelina

Commelina communis

flower

Commelina is a delicate ornamental flowering plant known for its striking blue three-petaled flowers that bloom in summer and fall. Native to East Asia, it produces charming ephemeral blooms that last only one day but appear in succession throughout the growing season. The plant features lance-shaped leaves and a spreading, somewhat sprawling growth habit.

When should you plant Commelina in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Commelina timeline →

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

  1. Plant Commelina

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Commelina blooms

    Around Jun 16

    ≈ 60 days after planting

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

Growing Conditions

☀️
Sun: Partial shade to full sun, 4-6 hours of sunlight daily
💧
Water: Keep soil consistently moist but not waterlogged; water regularly during growing season, reducing in winter if grown as perennial
📏
Spacing: 12-18 inches
📅
Days to maturity: 60-90
🌱
Planting depth: 1/4 inch for seeds; plant transplants at same depth as container

Soil

Type: Well-draining loamy soil
pH: 6.0-7.0
Amendments:
compost peat moss perlite for drainage

Growing Zones

Find your zone →

Thrives in zones 6-9; grows as annual in cooler zones

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

Sign up free to see if Commelina grows in your zone — and get a personalized planting timeline.

Get my Commelina timeline →

Growth Stages

1

Seedling

2-3 weeks

Tiny emerging plants with first true leaves appearing; very delicate at this stage

Keep soil moist and provide gentle indirect light; avoid overwatering which causes damping off

2

Vegetative

4-6 weeks

Plant develops multiple stems and lance-shaped green leaves; bushy spreading growth

Pinch back growing tips to encourage bushier form; maintain consistent moisture; feed with balanced fertilizer every 2-3 weeks

3

Flowering

8-12 weeks

Three-petaled blue flowers (sometimes with white or purple variations) appear at leaf axils; each bloom lasts one day but new flowers continuously emerge

Deadhead spent flowers to encourage more blooms; maintain steady watering and feeding; provide afternoon shade in hot climates

4

Seed Production

4-6 weeks

If flowers are not deadheaded, small seed capsules develop and mature to brown; seeds can self-sow

Allow some flowers to set seed if desired for next season; collect seed pods before they shatter

5

Dormancy (Perennial)

3-4 months

In zones 6-9, plant dies back or goes semi-dormant in winter; in tropical zones, growth may slow but plant persists

Reduce watering significantly; cut back dead growth; mulch in colder zones for winter protection

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

black walnut highly competitive aggressive growers

Common Pests

  • Increase humidity by misting; spray with neem oil or insecticidal soap; ensure good air circulation

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

  • Dab with alcohol on cotton swab; spray with neem oil; maintain good air circulation

  • and

    Hand-pick at night; use beer traps; apply diatomaceous earth around plants; remove hiding spots

Uses

🍳

Traditional Asian cuisine

Culinary

Commelina leaves and tubers are used in traditional East Asian cooking, particularly in Chinese cuisine where they are called 'dayflower.' The plant is valued as a nutritious green vegetable. [source]

💊

Traditional herbal medicine

Medicinal

In traditional Chinese medicine, Commelina is used to treat inflammation, fever, and respiratory conditions. The plant contains compounds believed to have cooling and detoxifying properties. [source]

🏠

Natural dye

Household

The blue flowers of Commelina can be used to create natural blue dyes for textiles and crafts, though the color is not entirely permanent. [source]

🏠

Cut flowers and arrangements

Household

Though ephemeral, the delicate blue flowers make charming additions to fresh flower arrangements and garden displays when cut early in the morning. [source]

🦋

Pollinator support

Wildlife

Commelina flowers attract bees and other pollinators, making it a valuable addition to pollinator gardens and supporting local ecosystems. [source]

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

Harvest Tips

Commelina is grown for ornamental flowers rather than harvest. Enjoy blooms in the garden or cut individual flowers for small arrangements early in the morning when they are freshest (though they will close by afternoon as they are ephemeral). Collect mature seed pods in late summer if you want to save seeds for next season.

Fun Facts

  • 🌱 Commelina flowers are true ephemeral flowers, blooming only for a single day—they open in the morning and close by afternoon, earning the common name 'dayflower.'
  • 🌱 The plant is named after the Commelin brothers, Dutch botanists and horticulturists of the 17th century; the three petals symbolize the three brothers, two prominent and one less visible.
  • 🌱 Commelina has been used for over 2,000 years in Asian traditional medicine and cuisine, making it one of the oldest cultivated plants in East Asia.

Gardening Terms

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

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Commelina planting timeline

Tell us your zip code and we'll calculate exactly when to start Commelina seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Commelina timeline →