Blue Flag Irises are native to marshes, swamps, wet meadows, and shorelines in the northeastern United States and Canada. Blue Flag Iris is a common addition to water gardens and water features, as it tolerates standing water up to 4 inches deep. Plants can also be grown in consistently moist garden soils in full sun to part shade. Plant in full sun to part shade, ideally with morning sun and afternoon shade. Plants need constantly moist soils and can be planted in up to 4 inches of standing water. Blooms open early to mid-spring and make long-lasting cut flowers. Plants can be trimmed back during the dormant season. Irises spread slowly by rhizomes to form dense clumps, and can be divided in early autumn. Wear gloves when handling rhizomes. Plants are deer and rabbit resistant, and toxic if consumed.