Blue Flag thrives in consistently moist soil. Water regularly, especially during dry periods, to maintain a swampy or bog-like environment. Avoid allowing the soil to dry out completely, as this can stress the plant.

Ensure good drainage to prevent root rot if not growing in its natural wet habitat.

After flowering, deadhead spent blooms to encourage reblooming or prevent seed production. In late fall or early spring, remove any dead, damaged, or yellowing foliage.

This helps maintain the plant's appearance and allows for healthy new growth in the upcoming season.

Blue Flag is easily propagated by division. In early spring or fall, carefully dig up the plant and separate the rhizomes. Ensure each division has at least one eye or shoot.

Replant divisions immediately into moist soil at the appropriate depth.

Blue Flag is a rhizomatous perennial that often prefers to be left undisturbed. If a container becomes overcrowded or the plant outgrows its pot, repot in early spring.

Choose a larger container and fresh, moist potting mix, replanting the rhizomes near the surface.