Iris virginica (Virginia or Southern Blue Flag)

Tried and True Native Plant Selections for the Mid-Atlantic 

Northern Blue Flag is native to Fairfax and Loudoun Counties and is similar in growth habit to Southern Blue Flag. Their flowers, which are difficult to tell apart, attract hummingbirds.
Video © 2016 Mary Free

The wetland species of Southern Blue Flag* and its close relative, Northern Blue Flag (Iris versicolor),** grow in fresh to mildly brackish tidal marshes and wet meadows of the Mid-Atlantic, but the former is mostly found from Virginia southward to Florida. Both native irises share similar growth habits and showy flowers that attract hummingbirds.

*I. virginica is native in DC and in Prince George’s and Kent Counties in MD. In VA, it is frequent to locally common in the Coastal Plain and infrequent to rare inland. In NoVA, it is native to Fairfax and Prince William Counties. It is pictured in full form and close-up above.

**I. versicolor is native in DC, DE, MD’s Anne Arundel and Calvert Counties, mostly the eastern and northwestern counties of PA, and northward into Canada. In VA, it is infrequent to rare in the mountains, northern Piedmont, and northern Coastal Plain. In NoVA, it is native in Fairfax and Loudoun Counties. 

Print Version (Legal Size): Iris virginica (Virginia or Southern Blue Flag)Iris virginica, Virginia Blue Flag, Perennial Plants & Flower,* Colony with Hummingbird** Height: 1–3 feet Spread: 1–2 feet Bloom Color: Light blue to deep violet Characteristics Upright, clumping herbaceous perennial Weakly arching, bright medium green, sword- shaped basal leaves rise from shallow roots Blue flowers with darker purple veins and bright yellow signals bloom on tall stalks from May to July Green to brown fruit capsule Spreads by rhizomes to form colonies Attributes Tolerates light shade, clay soil, and flooding No serious pests–but snails may eat foliage and muskrats eat rhizomes–or diseases; deer and rabbits rarely damage Ethnobotanic, therapeutic, and herbal uses Attracts bees, butterflies, skippers, hummers Growing and Maintenance Tips Soil Requirements: Wet, acidic soils Light Requirements: Sun Water Requirements: Moist, Wet Propagate by clump division in early fall when leaves begin to turn yellow (wear gloves) Use along water’s edge, in water garden, or in rain garden that is consistently moist to wet Hardiness: USDA Zones 5-9 Excellent Replacement for Iris pseudacorus - Yellow Flag Iris *I. virginica is native in DC and in Prince George’s and Kent Counties in MD. In VA, it is frequent to locally common in the Coastal Plain and infrequent to rare inland. In NoVA, it is native to Fairfax and Prince William Counties. It is pictured in full form and close-up above. **I. versicolor is native in DC, DE, MD’s Anne Arundel and Calvert Counties, mostly the eastern and northwestern counties of PA, and northward into Canada. In VA, it is infrequent to rare in the mountains, northern Piedmont, and northern Coastal Plain. In NoVA, it is native in Fairfax and Loudon Counties. It is pictured with a ruby-throated hummingbird above.
Learn more about other Mid-Atlantic plants: Tried and True Plant Fact Sheets.