Southern Blue Flag

About Southern Blue Flag

Southern Blue Flag is a robust and graceful iris that flourishes in the sunny wetlands and wet prairies of the Midwest and South. Reaching 2 to 3 feet in height, it produces large, fragrant flowers in shades of lavender to blue-violet. The blooms are distinguished by a bright yellow "signal" patch on the falls, which serves as a guide for pollinators like bumblebees and long-tongued flies. Flowering occurs from May to July, providing a mid-season burst of color. This species is highly adaptable, thriving in full sun to partial shade and wet to medium-moist soils; it can even handle several inches of standing water. Its dense, rhizomatous root system makes it excellent for erosion control along stream banks and pond margins. With its architectural foliage and reliable blooms, Southern Blue Flag is a versatile performer for any garden site that stays consistently damp, offering both aesthetic beauty and vital habitat for wetland wildlife.