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Commelina spp.

dayflowers

Commelinaceae

Pantropical; centres of diversity in Africa, Asia, and the Americas

Attracts Pollinators Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterMedium

HardinessZones 7–11

Overview

Commelina spp. is a genus of about 170 species of annual and perennial herbs in the family Commelinaceae, known as dayflowers because each bloom lasts a single day. Stems are often decumbent, rooting at the nodes, and reach 10-90 cm (4-35 in). The leaves are alternate, lance-shaped to ovate, 3-12 cm (1.2-4.7 in) long, with sheathing bases that clasp the stem. Flowers emerge from a folded, boat-shaped bract called a spathe. Most species bear two prominent petals, usually blue, above a smaller, often reduced third petal, though a few species are white or yellow. The flowers open in the morning and wilt to a fluid by afternoon. The fruit is a small capsule holding pitted seeds. Several species, including C. communis and C. benghalensis, are widespread weeds of cultivated ground, and C. benghalensis is a federally listed noxious weed in the United States. The genus is distributed across tropical and subtropical regions worldwide, with some species reaching temperate zones. Plants spread readily by rooting stems and by seed, forming dense patches in moist, disturbed soil.

Native Range

Distributed throughout tropical and subtropical regions worldwide, with centres of diversity in Africa, Asia, and the Americas. Some species range into temperate North America, where both native and introduced dayflowers occur. C. benghalensis, native to tropical Asia and Africa, has become an invasive weed in the southeastern United States.

Suggested Uses

Grown as groundcover and edging in moist borders and along water margins, and as a flowering annual in containers in cooler climates. Spreading habit suits naturalized and informal plantings where it can fill ground freely.

How to Identify

Identified by the folded, boat-shaped spathe enclosing the flowers and by blooms with two larger petals above a smaller third petal. Leaves have sheathing bases that wrap the jointed stems, which often root where they touch the ground. The single-day flowers and the fluid collapse of spent blooms are characteristic of the genus.

Appearance

Size & Dimensions

Height4" - 2'11"

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~12 weeks

Summer Fall

Flowering runs through summer into autumn in most species, with individual flowers lasting only one morning. New flowers open in succession over many weeks. In frost-free climates some species flower nearly year-round.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-8 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

loam clay sand

Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

1 season to flowering

Care & Maintenance

Care Guide

Dayflowers grow in full sun to part shade in moist, fertile soil and tolerate a range of textures from sand to clay. Consistent moisture produces lush growth, while drought causes stems to wilt and die back. Most species are frost-tender perennials grown as annuals where winters are cold. Stems root at the nodes, so plants establish quickly and can become weedy in irrigated ground. Spread is contained by clearing rooted stem fragments before they set seed.

Pruning

Cutting plants back during the growing season limits spread and brings on denser, more compact growth. Spent stems are sheared to the ground after frost in cold-winter regions. Clearing flower heads before seed set reduces self-sowing.

Pruning Schedule

summer