Introduction

This clumping, robust perennial has stiff leaves radiating up and out in a fan-shaped pattern. The flower spikes are topped with 3inch white flowers marked with yellow and blue. Although short-lived (about 2 days), the flowers are produced sporadically throughout the year, especially in spring and early summer. Plants grow to 4 or 5 feet tall in standing water, making it ideal for water gardens and wet soil. They reach about 2 to 3 feet in soil. African iris is also attractive when used as an accent planted in a shorter groundcover.

General Information

Scientific name: Dietes vegeta

Pronunciation: dye-EE-teez VEDGE-jet-tuh

Common name(s): African iris, butterfly iris

Family: Iridaceae

Plant type: herbaceous; ornamental grass

USDA hardiness zones: 8B through 11 (Figure 3)

Planting month for zone 8: year round

Planting month for zone 9: year round

Planting month for zone 10 and 11: year round

Origin: not native to North America

Invasive potential: not known to be invasive

Uses: border; mass planting; container or above ground planter; naturalizing; water garden; accent; suitable for growing indoors

Availability: generally available in many areas within its hardiness range

Description

Height: 2 to 6 feet

Spread: 1 to 2 feet

Plant habit: upright

Plant density: moderate

Growth rate: slow

Texture: fine

Foliage

Leaf arrangement: most emerge from the soil, usually without a stem

Leaf type: simple

Leaf margin: entire

Leaf shape: linear

Leaf venation: parallel

Leaf type and persistence: evergreen

Leaf blade length: 18 to 36 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: white

Flower characteristic: flowers periodically throughout the year

Fruit

Fruit shape: elongated

Fruit length: .5 to 1 inch

Fruit cover: dry or hard

Fruit color: green

Fruit characteristic: persists on the plant

Trunk and Branches

Trunk/bark/branches: typically multi-trunked or clumping stems

Current year stem/twig color: not applicable

Current year stem/twig thickness: not applicable

Culture

Light requirement: plant grows in part shade/part sun

Soil tolerances: extended flooding; slightly alkaline; clay; sand; acidic; loam

Drought tolerance: moderate

Soil salt tolerances: poor

Plant spacing: 24 to 36 inches

Other

Roots: not applicable

Winter interest: plant has winter interest due to unusual form, nice persistent fruits, showy winter trunk, or winter flowers

Outstanding plant: not particularly outstanding

Pest resistance: long-term health usually not affected by pests

Use and Management

African iris will bloom best on rich, moist soil but will tolerate moderately dry soil conditions, growing in full sun to partial shade. Plants in the full sun or in sandy soil grow best with regular and frequent irrigation. Cold temperatures (below 25°F) cause leaf browning. These leaves can be removed in the spring to clean up the plant. Otherwise, African iris requires no maintenance except for a light fertilization or two each year. Frequent fertilization increases growth rate, foliage color and flower production.

The cultivar 'Johnsonii' has larger leaves and flowers.

Propagation is by seed or division of the matted clumps. Whole plants are lifted, and the rhizomes divided every three years or when new plants are needed.

Pests and Diseases

Nematodes are the main pest problem. No other problems appear to affect this durable plant.

No diseases are of major concern.