How to prune siberian iris

Deadhead immediately after flowering (early summer); cut back foliage in autumn. Remove spent flower stalks at the base. In autumn, cut foliage to 4–6 inches. To divide, lift the clump, cut into sections each with healthy roots and fan of leaves, replant promptly.

Annually for deadheading and autumn cutback; divide every 3–5 years. Siberian Iris benefits from deadheading after flowering to keep clumps tidy. Cut flower stalks down to the base once blooms finish. In autumn, trim foliage back to 4–6 inches above ground. Divide congested clumps every 3–5 years in late summer for best flowering — this is the most impactful maintenance task.

Remove spent flower stalks at the base. In autumn, cut foliage to 4–6 inches. To divide, lift the clump, cut into sections each with healthy roots and fan of leaves, replant promptly.