FIRST IMPRESSIONS: Iris cristata ‘Powder Blue Giant’ is a diminutive mat-forming wildflower cultivar. Narrow pointed leaves arise from underground rhizomes and soon forms a lovely groundcover. In spring plants carpet the ground with myriads of blue-violet irises. This spring beauty prospers in woodland settings with average well drained soils.
HABITAT & HARDINESS: The parent species is native from Pennsylvania to Illinois and south to Georgia, Mississippi, Arkansas and Oklahoma.
Iris cristata is indigenous to rocky wooded slopes, deciduous calcareous woodlands, ravines, creek and stream banks, slopes of floodplain forests and on shaded bluffs and ledges.
‘Powder Blue Giant’ was discovered by plantsman Samuel Norris of Owensboro, Kentucky almost 40 years ago. The plant was found in a large stand of Iris cristata near Litchfield, Kentucky. It was introduced into the nursery trade in 1998 by Joe Pye Weed Garden, a Massachusetts nursery.
The cultivar is notable for its vigor, floriferous nature and flowers and foliage that are larger than normal for the species.
Plants are hardy in USDA Zones 5-8.
PLANT DESCRIPTION: Iris cristata ‘Powder Blue Giant’ is an award winning wildflower cultivar.
Plants form colonies as they expand from plump shallow rhizomes that are connected by slender runners.
Sword shaped 8-12” 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.
In mid-spring masses of 3” soft 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 golden ridges called a crest.
Plants are 8-12” tall with a 12-15” spread.
CULTURAL & MAINTENANCE NEEDS: Iris cristata ‘Powder Blue Giant’ grows best in partly shaded or shaded sites with rich well drained soil. Plants will tolerate some sun if soil is consistently moist.
This cultivar tolerates alkaline soil, rocky soil, dry shade and is pest resistant and unpalatable to deer and other herbivores.
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 ‘Powder Blue Giant’ is an excellent Accent plant for a Shade Garden or Shaded Rock Garden. In residential sites, small Groupings of plants can be located throughout shaded areas or Massed 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 ‘Powder Blue Giant’ 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 white flowering replacement
TRIVIA: Iris cristata ‘Powder Blue Giant’ won several American Iris Society awards including Honorable Mention in 2001, Award of Merit in 2003 and the SIGNA Medal in 2005.
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.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=IRCR