Tropical Iris Look-Alikes: Neomarica and Dietes for Warm Gardens and Indoors

Gardeners in temperate zones cherish iris, but those in subtropical and tropical climates need alternatives. Enter Neomarica (walking iris) and Dietes (African or Cape iris)—iris relatives that flourish in heat and humidity. Even northern gardeners can enjoy them as easy-care houseplants. Unlike true iris, whose tepals are fused at the base, these genera have six completely separate tepals. Neomarica further distinguishes itself with distinctly curled petals.

Walking Iris (Neomarica)

Native primarily to Brazil, Neomarica comprises about 15 species. Plants form dense clumps of sword-like leaves 60–150 cm long. Flowers appear singly over several days, each lasting only a few hours. Outdoors, they tolerate full sun to part shade; as houseplants, full sun encourages reliable blooms. Hardy to zones 9–10, they withstand indoor winter temperatures down to 15°C (60°F). Keep dry in winter, water freely in summer. Propagate by division or, for N. northiana and N. gracilis, by plantlets that form on flower stalks.

Key Cultivated Species

• N. brachypus and N. longifolia – Nearly identical; yellow flowers with a brown band, leaves 50–60 cm, flower stems exceeding leaf length.
• N. northiana and N. gracilis – Large, fragrant white flowers with intricate blue and brown markings. After blooming, plantlets form at stem tips, bend to the ground, and root—hence “walking iris.”
• N. caerulea – The giant of the genus, leaves up to 160 cm, pale blue to lilac fragrant flowers with yellow and brown markings.

Details of Neomarica gracilis (left) and N. northiana (right)

Details of Neomarica longifolia (left) and N. caerulea (right)

African Iris (Dietes)

Native to Africa, Dietes includes six species with narrow, grass-like foliage. Flowers last 1–3 days each, blooming sequentially over weeks—more floriferous than Neomarica. Slightly hardier (some to zone 8), they thrive in full sun and tolerate poor, dry soils. Propagate by division or seed; deadhead promptly to prevent aggressive self-seeding.

Common Dietes Species

• D. bicolor – 60–100 cm, cream-white flowers with blackish blotch and orange markings on outer tepals.
• D. grandiflora – Similar size, white to ice-blue flowers with large yellow base on sepals.
• D. iridiodes – Smaller (30–60 cm), resembles D. grandiflora. Native to Drakensberg Mountains at 2000 m; hardiest species, worth trying in zone 7b with thick mulch.
• D. robinsoniana – Giant to 2 m, most tender. Large white flowers with distinct orange-yellow blotch, sweet honey fragrance.

Details of Dietes iridiodes (left) and D. grandiflora (right)

Details of Dietes robinsoniana (left) and D. bicolor (right)

Whether you garden in the tropics or grow indoors, Neomarica and Dietes bring iris-like elegance to warm climates.

Photo credits: gregcutler (N. northiana), jamieau (D. bicolor), pongsak (D. robinsoniana), snuzi (D. grandiflora).