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Commelina erecta

whitemouth dayflower

Commelinaceae Americas and parts of Africa

Attracts Pollinators Deer Resistant Drought Tolerant Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterLow · drought-tolerant

HardinessZones 5–10

Overview

Commelina erecta is a herbaceous perennial in the spiderwort family, growing 8-39 inches (20-100 cm) tall from a cluster of fleshy roots. Stems are erect to sprawling, branched, and somewhat succulent, rooting where lower nodes touch the ground. Leaves are linear to lance-shaped, 2-6 inches (5-15 cm) long, with sheaths that clasp the stem. Each flower has two rounded upper petals in clear blue and a much smaller, often white lower petal, opening from a folded green spathe shaped like a boat. Individual flowers last a single morning, closing by afternoon, but plants bloom in succession from late spring through autumn. The blue color and the reduced white lower petal give rise to the name whitemouth dayflower. Plants grow in dry, sandy, or rocky open ground and tolerate heat and drought once established. The species self-seeds and can spread into a loose colony, becoming weedy in cultivated beds. Bees collect pollen from the flowers in the morning hours. The fleshy roots make it slow to remove once settled.

Native Range

Commelina erecta is native to the Americas and parts of Africa, ranging across the eastern and central United States, south through Mexico and Central America into South America. It grows in sandy woodlands, prairies, dunes, and disturbed open sites.

Suggested Uses

Used in wildflower meadows, native plantings, and sandy or gravel gardens, spaced 12-18 inches (30-45 cm) apart. It suits naturalized areas where its spreading habit is not a concern. The flowers add blue color to summer borders.

How to Identify

Flowers have two rounded blue upper petals and a smaller pale lower petal, emerging from a folded, boat-shaped green spathe with fused lower edges. Leaves are narrow and lance-shaped with stem-clasping sheaths fringed with red hairs at the top. Each bloom lasts only a single morning.

Appearance

Size & Dimensions

Height8" - 3'3"

Width/Spread1' - 2'

Reaches mature size in approximately 1 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~20 weeks

Summer Fall

Flowers open in the morning from May through October and close by afternoon. Each bloom lasts one day, but new flowers open in succession over many weeks. The boat-shaped spathe encloses the developing buds and seed capsules.

Detailed Descriptions

Flower Description

blue with white lower petal

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

sand loam rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

1 year from seed

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun to part shade in dry, sandy, or rocky soil with sharp drainage. Once established they tolerate heat, drought, and poor fertility, and need little supplemental water. Rich or wet soil encourages lank, sprawling growth and heavier self-seeding. The fleshy perennial roots resprout each spring and can be slow to dig out. Plants spread by seed and by rooting stems, forming loose colonies. Hardy in USDA zones 5 to 10.

Pruning

Cutting plants back after the first flush keeps growth compact and can prompt fresh blooms. Stems can be sheared to the ground in late autumn once the foliage dies back. Removing seed capsules before they ripen limits self-seeding.

Pruning Schedule

fall