Trimezia spp.

walking irises

Iridaceae Tropical and subtropical Americas

Attracts Pollinators Attracts Butterflies Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterMedium

HardinessZones 9–11

Overview

Trimezia spp. is a genus of evergreen, rhizomatous perennials in the family Iridaceae, native to Mexico, Central America, the Caribbean, and tropical South America. Plants form clumps of flat, sword-shaped leaves 12 to 36 inches (30 to 90 cm) long arranged in a fan, resembling those of bearded iris but thinner. Flowering stems carry a succession of short-lived iris-like flowers, each open for about a day, with three spreading outer segments and three smaller inner ones. Across the genus the flowers are mostly yellow, often marked with brown or maroon spotting toward the center. After flowering, some species form plantlets at the tip of the stalk; the weight bends the stem to the ground, where the plantlet roots and forms a new plant, the behavior behind the name walking iris. The genus grows in tropical woodland, savanna, and rocky ground, and most species need frost-free conditions, dying back or failing where temperatures drop below freezing. Plants tolerate part shade and bloom over a long warm season. A limitation is the brief life of each flower, though new buds open in sequence over many weeks.

Native Range

Trimezia spp. is native to the tropics and subtropics of the Americas, from Mexico and the Caribbean through Central America to Brazil and Argentina. Species grow in seasonally moist woodland, grassland, and rocky outcrops.

Suggested Uses

Trimezia spp. is used as an evergreen clumping perennial in tropical and subtropical borders, as an understory planting in part shade, and in containers in cooler regions. The fans of foliage and sequential flowers suit mixed beds and poolside plantings in frost-free climates.

How to Identify

Identify Trimezia spp. by its fans of thin, sword-shaped leaves and its branched flower stalks bearing iris-like flowers with three larger outer segments and three smaller, often incurved inner segments. The flowers are predominantly yellow with brown or maroon central markings. Plantlets forming at the stalk tip, which root where they touch the ground, separate Trimezia spp. from true Iris spp..

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~20 weeks

Spring Summer Fall

Trimezia spp. blooms over a long period in warm weather, mainly spring through fall and year-round in frost-free climates. Each flower lasts about one day, with new flowers opening in succession on the same branched stalk over several weeks.

Detailed Descriptions

Flower Description

yellow with brown markings

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 Range6.0 - 7.0(Neutral)

357912

Soil Types

loam sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

1-2 years

Care & Maintenance

Care Guide

Across the genus, Trimezia spp. grows in full sun to part shade in moist, well-drained soil rich in organic matter, with soil pH from about 6.0 to 7.0. Plants need frost-free conditions and are grown in containers and moved under cover where winters are cold. Consistent moisture during the growing season supports continuous flowering, while drainage prevents rhizome rot in wet soil. Propagation is by division of the rhizomes or by rooting the plantlets that form on the flower stalks. In containers a loam-based mix is used and clumps are divided when they fill the pot. Foliage remains evergreen in mild climates.

Pruning

Spent flower stalks can be removed once flowering ends and any plantlets have been harvested. Damaged or browned leaves are trimmed at the base. Crowded clumps are divided in spring to maintain flowering.