Iris virginica
 
Common Names: Southern Blue Flag, Virginia Iris, Water Iris, Blue Flag Iris
 
Zones: 5–10
 
A moisture-loving perennial native to the eastern United States, Iris virginica thrives in marshes, wet meadows, and streambanks from New York to Florida and west to Texas. Known for its elegant blue to violet flowers and sword-like foliage, it adds vertical interest and seasonal color to wetland gardens and restoration zones. This species supports pollinators and stabilizes soils in saturated habitats.
 
Key Features
Growth Habit: Clump-forming; rhizomatous; dies back in winter
Height: Typically 2–3 ft (0.6–0.9 m); flower stalks may reach 4 ft (1.2 m)
Trunk: Herbaceous; green; emerges from thick rhizomes
Leaves: Sword-shaped; bright green; 1–2 ft (30–60 cm) long; arranged in fans
Inflorescence: Showy blue to violet flowers with yellow and white markings; bloom late spring to early summer
Fruit: Elongated capsules; contain numerous seeds; not typically ornamental
Ecology: Native to freshwater wetlands and riparian zones; attracts pollinators; stabilizes soil
 
Growing Conditions
Light: Full sun to part shade
Watering: High; thrives in saturated or seasonally flooded soils
Soil: Rich, loamy, or silty; tolerates clay; prefers wet conditions
Temperature: Tolerates –20 to 95°F (–29 to 35°C); thrives in 65–85°F (18–29°C)
Humidity: High; adapted to humid subtropical zones
Propagation: By rhizome division or seed; easy to establish
Tolerance: Flood-tolerant; deer-resistant; suitable for pond margins and rain gardens
 
Landscape Use
Best suited for wetland restorations, pond edges, rain gardens, and native borders. Its graceful flowers and upright foliage offer visual impact and ecological value. Pairs well with Pontederia cordata, Lobelia cardinalis, and Carex stricta in moisture-rich, pollinator-friendly designs.