Southern Blue Flag Iris
Iris virginica
Last reviewed: June 2026
Southern Blue Flag Iris (Iris virginica) is a native wetland perennial producing violet-blue flowers from March through August across the eastern and central United States.
Southern Blue Flag Iris is toxic to dogs and cats.
Listed as toxic by the ASPCA Animal Poison Control Center (opens in new tab) (last reviewed 2026-05-21). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435and your veterinarian's emergency line.
Pollinator Patch flags toxic plants so you can choose a pet-safe native alternative for your yard.
The USDA PLANTS Database (opens in new tab) does not flag Southern Blue Flag Iris as toxic to livestock.
Light
full sun
Water
high
Size
24"–36" H × 12"–24" W
Bloom
Mar, Apr, May, Jun, Jul, Aug
Native to
AL, AR, FL, GA and 23 more states
Pollinators
butterflies, bees, hummingbirds
Browse plants for this ecoregion
Southern Blue Flag Iris produces striking blue to purple flowers with yellow markings from spring through summer. This moisture-loving perennial forms upright clumps of sword-like leaves and thrives in consistently wet soils or shallow water features.
Growing Southern Blue Flag Iris
Grow Southern Blue Flag Iris in full sun and high water. Mature plants reach 24 to 36 inches tall and spread 12 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Southern Blue Flag Iris is an HOA-friendly choice. Maintenance level: low. Tidiness: 4 out of 5.
Works well in: front yard, foundation, street edge, mid zone.
Wildlife value
The showy flowers attract butterflies, bees, and hummingbirds throughout the extended blooming season. Seeds provide food for waterfowl and other birds.
Common questions
- When does Southern Blue Flag Iris bloom?
- Southern Blue Flag Iris blooms from March through August, with peak flowering typically occurring in late spring to early summer.
- What growing conditions does Iris virginica prefer?
- This iris thrives in full sun to partial sun with consistently moist to wet soil conditions, making it ideal for pond edges, wetlands, and rain gardens.
- What pollinators visit Southern Blue Flag Iris?
- The flowers attract butterflies, bees, and hummingbirds, providing nectar and serving as an important native pollinator plant.
- Where is Iris virginica native?
- Southern Blue Flag Iris is native to 27 states across the eastern and central United States, from Florida north to New York and west to Texas and Minnesota.
- Is Southern Blue Flag Iris toxic to dogs?
- Yes. Southern Blue Flag Iris is listed as toxic to dogs by the ASPCA Animal Poison Control Center (aspca.org). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Southern Blue Flag Iris toxic to cats?
- Yes. Southern Blue Flag Iris is listed as toxic to cats by the ASPCA Animal Poison Control Center (aspca.org). If your cat has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Southern Blue Flag Iris toxic to livestock?
- The USDA PLANTS Database does not flag Southern Blue Flag Iris as toxic to livestock.
- Is Southern Blue Flag Iris HOA-friendly?
- Southern Blue Flag Iris is generally an HOA-friendly choice in the right placement, with low maintenance.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Pollinator Patch flags toxic plants like Southern Blue Flag Iris and shows pet-safe natives for your ecoregion instead.