Roof iris (Iris tectorum)

Roof iris

Features and Characteristics

Iris tectorum is a 15″ tall species of the crested iris group featuring large, 6″ across, beardless, bright lilac-purple flowers with falls which are crested white. Foliage is arranged in fans of narrow, lance-shaped, ribbed, glossy, upright leaves that can become somewhat floppy. Can spread rapidly in the garden. Commonly called roof iris because it has in the past been grown on thatched roofs in both Japan and China.

Genus named for the Greek goddess of the rainbow.

Specific epithet means of the roofs of houses.

Care and Maintenance

Grow in organically rich, medium moisture, well-drained soil in full sun to part shade. Prefers sheltered sunny locations, as near a south or west facing wall. Plant rhizomes only about 1-2″ below the soil. Rhizomes tend to push out of the ground and will benefit from fall and spring mulches.

Roof iris (Iris tectorum) Requirements

Hardiness zone	4 - 9
Sun light	Full sun to part shade
Water	Medium
Maintenance	Low

Common Problems

Susceptible to a virus which discolors the leaves badly. Remove and destroy infected plants. Seed will be virus-free and can be collected for future planting. Also subject to slugs.

Uses

Because of its preference for sheltered, sunny areas, this iris can solve a planting problem in areas of the garden where there is limited air circulation. It also may be effective when planted in the rock garden or in large drifts at the front of the perennial border. The ribbed leaves add texture to the garden.

Roof iris (Iris tectorum) Details

Common name	Roof iris
Botanical name	Iris tectorum
Plant type	Herbaceous perennial
Family	Iridaceae
Hardiness zone	4 - 9
Water	Medium
Maintenance	Low
Flower color	Deep lilac-blue purple with white crest
Flowering period	May
Height	1 - 1.50 feet
Width	1 - 1.50 feet