When someone says "ground cover", iris is not usually the plant that jumps to mind. Dwarf crested iris does make a good ground cover. It grows only 6 or 7 inches tall and forms a dense mat.
This plant has some cultivated varieties. Go to list of cultivars.
All Common Names:
Tree or Plant Type:
- Ground cover,
- North America
- Mixed border,
- Small plant (6-12 inches)
- Full sun (6 hrs direct light daily),
- Partial sun/shade (4-6 hrs light daily)
- Zone 3,
- Zone 4,
- Zone 5 (Chicago),
- Zone 6,
- Zone 7,
- Zone 8
- Moist, well-drained soil
- Dry sites,
- Alkaline soil
Season of Interest:
- Early spring,
- Mid spring
Flower Color & Fragrance:
Shape or Form:
Size and Method of spreading
Dwarf crested iris grows 3 to 6 inches high and is a colonizing ground cover. Colonizing ground covers produce underground stems that spread out horizontally and shallowly, produce roots and then send up new shoots. These plants are strong growers and may have the potential to grow aggressively.
Best growth is in partial shade, but this plant can adapt to full sun as long as the water supply is adequate. Too much water can lead to rot of the rhizomes and decline of the plants. Excess fertilizing can promote growth of foliage at the expense of the flowers.
Disease, pests, and problems
Slugs and iris borers can be a problem. Soft rot and rhizome rot can occur, especially in wet sites.
Disease, pest, and problem resistance
Resistant to deer.
Native geographic location and habitat
Native to several Eastern and Southeastern states.
Leaves are narrow and strap-like, with entire margins. They arise from the base of the plant.
The flower is the typical iris flower, but smaller than other species. They are blue or violet and marked with white and yellow. Flowers are produce in early to mid-spring.
The fruit is a capsule; not ornamentally important.
Cultivars and their differences
Abbey's Violet dwarf crested iris (Iris cristata 'Abbey's Violet'): Darker violet-blue flowers.
Eco Bluebird dwarf crested iris (Iris cristata 'Eco Bluebird'): Lavender-blue flowers and more vigorous growth.
White-flowered dwarf crested iris (Iris cristata 'Alba'): White flowers marked with yellow.