Iris, Genus, japonica, Species,
- Genus & species
Fringed iris
Overview
Iris japonica is an evergreen, rhizomatous perennial in the iris family (Iridaceae), forming fans of leaves 12–24 inches (30–60 cm) tall that spread by slender stolons to 18–36 inches (45–90 cm) wide. Leaves are sword-shaped, glossy dark green, 12–24 inches (30–60 cm) long and 1–1.5 inches (2.5–4 cm) wide, with no midrib. Flower stalks are branched, 12–24 inches (30–60 cm) tall, and carry flowers 1.5–2 inches (4–5 cm) wide that are pale lavender-blue to white, with a ruffled, fringed orange crest and violet markings on the falls. Each flower lasts 1 day, and a stalk produces flowers over 2–3 weeks. Fruits are seldom formed, and spread is by stolons. Foliage is damaged below 10°F (−12°C), and plants flower sparsely in dry shade. Rhizomes and leaves contain compounds that irritate the digestive tract of pets.
Native Range
Iris japonica is native to central and eastern China and to Japan. It grows in shaded woodland, on slopes, and along streams.Suggested Uses
Used as an evergreen groundcover in woodland gardens and shaded borders in zones 7–10, spaced 18–24 inches (45–60 cm) apart. Plants are also grown in containers.How to Identify
Appearance
Size & Dimensions
Height1' - 2'
Width/Spread1'6" - 3'
Bloom Information
Flowers open from March to May on branched stalks 12–24 inches (30–60 cm) tall. Each flower lasts 1 day, and a stalk produces flowers over 2–3 weeks. Flower buds are damaged by freezes below 20°F (−7°C).
Detailed Descriptions
Flower Description
Pale lavender-blue to white with an orange crest and violet markingsFoliage Description
Glossy dark greenGrowing Conditions
Sun Requirements
Requires 3-6 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
Care & Maintenance
Care Guide
Grows in part shade in moist, humus-rich, well-drained loam with a pH of 5.5–7.0. Hardy in USDA zones 7–10, with foliage damage below 10°F (−12°C). Plants receive 1 inch (25 mm) of water per week, and established clumps tolerate short dry periods. Clumps are divided every 3–4 years in early fall or after flowering. Slugs and snails chew leaves, and rhizomes rot in wet, poorly drained soil.Pruning
Pruning is limited to cutting spent flower stalks at the base after flowering and removing damaged leaves in spring. Stolons are cut to limit the spread of clumps.Pruning Schedule
Prune: May–June
late spring
Container Growing
Suitable for container growing
Minimum container size: 3 gallons
