Japanese roof iris has broad purple flowers marked with a fringed white crest, above fans of ribbed leaves that spread from rhizomes.
- Height
- 30–46 cm / 1–1.5 ft
- Spread
- 30–46 cm / 1–1.5 ft
- Light
- Full sun / Partial shade
- Soil moisture
- Dry
- Flowering
- Spring
- Maintenance
- Low
- USDA zones
- 4a–9b
Planting
Choose sun or partial shade and rich, well-drained soil. A sheltered position beside a wall suits it; spreading rhizomes can form groups in naturalised planting.
Care
Apply winter mulch for protection. Divide spreading rhizomes to increase the planting, and check new growth for slugs.
Before planting: Harmful if swallowed; seeds, rhizomes and sap may irritate skin. Wear gloves when handling.
Planting Japanese roof iris?
Find a landscaper nearby to help with planting and establishment.
Find a landscaperMore plants to explore
Sources & photo credit
Plant reference: NC State Extension Gardener Plant Toolbox. Content checked . Flowering seasons vary with local climate; USDA zones describe winter cold tolerance.
- Japanese roof iris: Photo by Jason Sturner · CC BY 2.0. Resized, converted to WebP and cropped for display.
- Dwarf crested iris: cultivar413c · CC BY 2.0. Resized, converted to WebP and cropped for display.
- Northern blue flag: Danielle Langlois · CC BY-SA 3.0. Resized, converted to WebP and cropped for display.
- Siberian iris: Cathy Dewitt · CC BY 4.0. Resized, converted to WebP and cropped for display.