Native to North America
NO ADVANCE ORDERS (NAO) - A selection of plants are NAO-No Advanced Orders. They have proved to be tricky; acquiring propagules, producing them, or getting them through the winter. We only put them on our availability lists when they are ready to ship. No hopes dashed. Plants must ship within 2 weeks or their availability date.
FIRST IMPRESSIONS: This diminutive mat-forming wildflower has narrow pointed leaves. The distinctive foliage arises from underground rhizomes and soon forms a lovely groundcover. In spring plants carpet the ground with myriads of small blue-violet irises. This spring beauty prospers in woodland settings with average well drained soils.
HABITAT & HARDINESS: This lovely iris is native from Pennsylvania to Illinois and south to Georgia, Mississippi, Arkansas and Oklahoma.
Plants are indigenous to rocky wooded slopes, calcareous woodlands, ravines, creek and stream banks, slopes of floodplain forests and on shaded bluffs and ledges. The overstory trees are deciduous hardwoods often dominated by oaks.
Plants are hardy in USDA Zones 3-8.
PLANT DESCRIPTION: Iris cristata is a much beloved wildflower that often forms colonies. New plants are formed from plump shallow rhizomes that are connected by slender runners.
Short sword shaped leaves arise from the rhizomes. They are gray-green or bluish. Leaves overlap at the base and fold around the adjacent leaf to form a flat fan-like arrangement. The blades tips bend in a delicate arch.
In mid-spring masses of small blue-violet blossoms appear. The blooms have a typical iris form with 3 drooping sepals called “falls” and 3 small upright petals called “standards”. The falls are marked with a white splotch or signal that surrounds three parallel orange ridges called a crest.
Plants are 6-8” tall with a 15” spread.
CULTURAL & MAINTENANCE NEEDS: Iris cristata grows best in partly shaded or shaded sites with rich well drained soil. Plants will tolerate some sun if soil is consistently moist.
This iris tolerates alkaline soil, rocky soil and dry shade.
This species is pest resistant except for occasional problems with snails and slugs. Foliage is unpalatable to deer and other herbivores.
In garden situations, plants benefit from the addition of rich compost or mulch. Lime is also welcome if woodland soils are strongly acidic. Plants can be divided every 3 to 4 years in fall if needed.
LANDSCAPE USES: Iris cristata is an excellent Accent plant for a Shade Garden or Shaded Rock Garden. In residential sites, locate small Groups of plants throughout shaded areas or Mass them into a spectacular Groundcover planting. Plants provide Attractive Foliage, showy Spring Flowers and Erosion Control. This species is a valuable component of Cottage Gardens, Deer Resistant Plantings, Water-wise Landscapes, Low Maintenance Plantings, Perennial Borders and Wildlife Gardens
COMPANION & UNDERSTUDY PLANTS: In woodland settings Iris cristata mingles cheerfully with Aquilegia canadensis ‘Corbett’, Chrysogonum virginicum, Phlox divaricata and Tiarella cordifolia. Woodland sedges like Carex plantaginea or Carex flaccosperma and native ferns like Athyrium filix-femina or Polystichum acrostichoides make good foliage companions.
In some garden situations, Iris cristata ‘Tennessee White’ could serve as a replacement if needed. Phlox divaricata could substitute as a groundcover with similar flower color, bloom time and cultural needs.
TRIVIA: Iris cristata and the rare Iris lacustris are the only two species of crested iris native to North America.
Iris cristata flowers are pollinated by native bees and are also attractive to hummingbirds.
Like most irises, the rhizomes and leaves of this species are poisonous. Ingestion can cause stomach pains and vomiting and handling can cause dermatitis.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=IRCR