Perennial · North Texas care guide
Iris germanica
Nursery Pro tip: Plant the rhizome shallow, like a duck on water. Old-fashioned and indestructible.
Ruffled spring flowers in nearly every color over fans of blue-gray sword foliage that looks good all season. Old Texas passalong plants, tough as nails, and many modern varieties rebloom in fall.
Full sun — six hours minimum — and sharp drainage. Space 12–18 in apart. Never plant them where a downspout or sprinkler keeps the soil wet.
Late summer through fall is the right window for rhizomes. The critical rule: set the rhizome so its top is visible at the soil surface, not buried, with the roots spread below. Potted plants go in at the same depth they grew. Keep mulch off the rhizome entirely.
Weekly while rooting and during spring bloom; almost none in summer. They want a dry rest after flowering.
Bone meal or a low-nitrogen fertilizer in early spring and again after bloom. High nitrogen causes rot.
Cut flower stalks to the base after bloom. Trim dead or spotted leaves any time; cut the fans back by half when you divide. Divide every three or four years in late summer — cut the rhizomes apart, discard the old woody centers, and replant the vigorous ends.
Rhizome rot from planting too deep, mulching over them, or too much water — the number-one problem. Iris borer, and leaf spot in wet springs.
Front of a sunny border with daylilies, salvia and Russian sage; beautiful against a stone wall.
Written for Rockwall's black clay, heat and winters by the Landscape Source team. Every yard is different — bring a photo by, or ask LS-Ai, and we'll tailor it to your spot.