FIRST IMPRESSIONS: Iris cristata ‘Alba’ is a diminutive mat-forming wildflower with narrow pointed leaves. The distinctive foliage rises from underground rhizomes and forms a lovely groundcover. In spring plants carpet the ground with myriads of small white irises. This iris prospers in woodland settings with average well drained soils.
HABITAT & HARDINESS: This spring beauty is a white variation of the native Iris cristata. White variations occur occasionally in wild populations from Pennsylvania to Illinois and south to Georgia, Mississippi, Arkansas and Oklahoma.
Plants may be 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 ‘Alba’ is a lovely wildflower that can form a small colony in good growing conditions. 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 clear white 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 three parallel golden ridges called a crest.
Plants are 6-8” tall with a 15” spread.
CULTURAL & MAINTENANCE NEEDS: Iris cristata ‘Alba’ 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.
Plants are 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.
LANDSCAPE USES: Iris cristata ‘Alba’ 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 ‘Alba’ mingles cheerfully with Aquilegia canadensis, 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 garden situations, Iris cristata ‘Tennessee White’ could be substituted if needed.
TRIVIA: Also known as Iris cristata var. alba. The Latin name for this color variation would no longer be accepted due to nomenclature guidelines that were adopted in 1959. The name was in use prior to 1959, however, so it is grudgingly accepted.
Iris cristata ‘Alba’ flowers are pollinated by native bees and are also attractive to hummingbirds.
This plant is a No Advance Order plant, which means it is only available to order when the plant appears on our Availability and must be shipped within 2 weeks of ordering. We are more than happy to add you to a list to contact you when the plants become available. We cannot offer approximate dates of when the plants will be available next.