JC Raulston Arboretum at
North Carolina State University
Raleigh, North Carolina
Agricultural Research Technician
Department of Horticultural Science
JC Raulston Arboretum
General Introductory Notes and Acknowledgements
Understanding Our Data
Plant Material Sources
The Perennials Trial was first planted in the Spring 2011. The Perennials Trial were created in direct response to grower, plant industry and homeowner interest. They are located adjacent to the Color Annual Plant Trials at NC State University within the JC Raulston Arboretum (JCRA) in Raleigh. The JCRA is a ten and a half acre site administered by the Department of Horticultural Science and located on 35° 47'N latitude, longitude 78° 42' W, with an elevation of 400 feet.
Plants to be entered into our trials are received in one of 3 ways- seeds, rooted cuttings/plugs or finished plants/pot. Virtually all are grown within controlled greenhouse environments prior to placement in protected outdoor structures for hardening off. Plant spacing in the trials is based on the estimated mature size of entrant that fits to a 4' x 4' area or by the number of plants sent. Each entry is evaluated for two complete calendar years, being removed after the spring flush in year three. After the plants are established, they are evaluated for hardiness and landscape performance with ratings regularly taken.
We thank the vegetative and seed companies that participate in our trials. The services we provide would not be possible without the cooperation and support of these companies. We appreciate this confidence and trust and we look forward to continuing our partnership.
Lastly, we are thankful to other departmental staff and the volunteers of the JC Raulston Arboretum who assisted in transplanting and maintaining the plants … we couldn't have done it without you all!
Danziger Flower Farm
Sakata Seed America
We also thank the following companies for their support of material donations:
Trials are conducted in amended beds. Prior to planting, beds are fertilized with 10-10-10 granular fertilizer and tilled. Depending on requirements plants are placed either in the shade structure or fully exposed in the sun. All plant material is mulched with composted leaf mulch to a 2-3” depth after planting. Pre-emergent herbicides are used at the initial planting and repeated each subsequent spring/summer season. Hand weeding is done at all other times. Later in the season, a post-emergent herbicide application along the edge of the beds was done on an as needed basis. An in-ground irrigation system delivers 1 to 1½ inches of water to the beds each week. Plant height and width measurements (recorded in inches) are taken twice during the growing season, usually at the end of June and again at the end of July. Data was collected from a representative plant, not the largest or the smallest but an average plant. Dormant plants were cut back in the fall/early winter to clean up the area and reduce overwintering habitat for insects and diseases.
The purpose of our perennials trial is to evaluate the plant material under conditions unique to our location. Our summer growing conditions are typically hot temperatures with high humidity. There is little nighttime temperature relief/recovery; average summer nighttime temperatures can be in the 70s. Irrigation is required all season.
Plants were given a visual rating by the same person. The overall rating was based on plant performance and appearance, including floriferousness, plant size and shape, and freedom from insect and disease problems. The rating scale ranged from 1 (very poor) to 5 (excellent) with 0.5 unit increments possible; a 0 rating indicated that all plants of the cultivar trial died.
Most entries were planted into their permanent trial location on:
2011 entries on April 29, 2011, and the heuchera, which arrived during the heat of summer, were potted up and place in shade until early fall (2011) when they were planted in beds.
2012 entries on April 10, 2012, and the rose entries were planted on September 25, 2012.
Armeria pseudarmeria 'Ballerina Lilac'/Ballerina®™ Lilac
Delphinium chinensis 'Diamonds Blue'
Dianthus (Bouquet™ Purple)
Heuchera (Kira™ Tropical Forest)
Lavandula angustifolia 'Ellagance Snow'/Ellagance®™ Snow
Scabiosa columbaria 'Mariposa Violet'
The best way to really evaluate our trials is to come in person. The JCRA is open 365 days a year.
Summer 2011 was extremely hot with long stretches of temperatures over 90°F and multiple days exceeding 100°F, including a record-breaking five consecutive 100°F+ days. This heat was followed by periods of normal temperatures with heavy rain.
The winter season (2011–2012) was very mild. During the month of December, we broke two high temperature records and had one tie for minimum temperature. In January, we experienced several periods of back-to-back nights with low temperatures ranging from 20°F–28°F. Our first and only snowfall occurred on February 19.
During the summer season of 2012 we experienced long periods of temps over 90°F with 10 days at/over 100°F. In the month of July, our average night temperature was 74°F. Periodic, heavy rainfall (over 8" in July and September) also plagued this season.
The winter season (2012–2013) was one of fluctuating temperatures. The early parts of the season (end of October, November and December) temperatures were slightly warmer than normal. January was mild but February began a cold period with March being unseasonably cold. The average temperatures in March were lower than our historical temperatures by double digits! We experienced three snow events.
Danziger Flower Farm, 102 Doan Avenue North, Painesville, OH 44077
Foremostco, Inc., 8457 NW 66th Street, Miami, FL 33166
Kieft-Pro-Seeds, P.O. Box 335, West Chicago, IL 60185
PanAmerican Seed, P.O. Box 335, West Chicago, IL 60185
Proven Winners, 1021 River Ridge Lane, Saint Thomas, MO 65076
Sakata Seed America, 18095 Serene Drive, Morgan Hill, CA 95037
Skagit Gardens, 3100 Old Highway 99 South, Mount Vernon, WA 98273
Please get in touch with these companies if you have specific questions regarding individual species and cultivars.
Baptisia 'Lemon Meringue'
Decadence™ hybrid wild-indigo
Flowers are a clear yellow color; blooms early- in April; foliage provides interest after bloom. We experienced a problem with genista broom moth caterpillars (Uresiphita reversalis); they ate all the foliage by July 2012, regrowth occurred in September 2012.
Echinacea purpurea 'Little Annie'
Well-branched, compact plants with a long bloom period; flower color is lavender-pink.
Armeria pseudarmeria 'Ballerina Lilac'
Died the first season (in July), never established.
Echinacea purpurea 'PowWow White'
Well-branched, compact plants with a long bloom period; flower color is a clear white.
Echinacea purpurea 'PowWow Wild Berry'
Well-branched, compact plants with a long bloom period; flowers are an attractive rose-purple color.
Heuchera 'Alpine Forest'
Good fall foliage color; forms a neat mound of lobed, dark silvery-green leaves with dark purple undersides.
Heuchera 'Autumn Leaves'
Good fall foliage color; forms a tidy mound of leaves that are red in the spring, turn taupe in the heat of summer, and deep red in the fall.
Heuchera 'Evergreen Forest'
Good fall color—yellows and reds mixed in with the green leaves; has a mounding habit.
Heuchera 'Fern Forest'
Good fall foliage color; forms a mound of green and silver leaves.
Heuchera 'Purple Rain Forest'
Good fall foliage color; forms a mound of purple with silver-cast leaves.
Heuchera 'Tropical Forest'
Died Summer 2012. Forms an attractive mound of green leaves with a silver-cast.
Mound of deep green leaves; golden-yellow flowers with a red eye; blooming period from June to August; maintenance free.
Delphinium chinensis 'Diamonds Blue'
Died the first season. Attractive blooms; flower color is an eye catching deep blue.
Bouquet™ Purple dianthus
Died 2012 summer. Compact mounding habit; fragrant flowers that are a deep rose color; long bloom period from spring to fall.
Dianthus 'Pomegranate Kiss'
Low maintenance; flower color is red with splashes of pink; a fragrant (spicy) double flower; blue-green, grassy foliage that keeps it's color year round; mounded form.
Gaillardia ×grandiflora 'Mesa Bright Bicolor'
Uniform and well-branched plants- do not lodge; flowers are a bright yellow with a red center ring that do not fade as the season progresses; long bloom season- from April through late fall.
Gaillardia ×grandiflora 'Mesa Yellow'
Low maintenance; uniform and well-branched plants—do not lodge; flowers are a bright yellow that do not fade as the season progresses; long bloom season- from May to late fall.
Hibiscus 'Cranberry Crush'
An abundance of large (7”–8” dia), deep scarlet red flowers on uniform plants; leaves have a reddish cast and are deeply lobed; colorful foliage for fall interest. We cut plants back after all leaves had dropped in the fall, but since this plant does not leaf out until spring, pruning foliage any time in the spring before new growth appears is acceptable. (The thick stems are woody, so a sharp pair of loppers is needed to cut through them).
Hibiscus moscheutos 'Luna Red'
Large, dinner-plate sized (7”–8” dia), red flowers on uniform plants; individual flowers last only one day; slow to emerge in the spring but once new growth begins it leaps.
Hosta 'Autumn Frost'
The leaves are an attractive frosty blue with a bright yellow margin; small light lavender flowers; struggled until this year (2013), when it finally started to shine!
Lavandula angustifolia 'Ellagance Snow'
Died summer 2012. Fragrant, large white flowers on uniform, bushy, well branched plants; both plant and flowers are fragrant; long flowering season- starts in June ends in early fall.
Phlox paniculata 'Shockwave'
Died fall 2012. Attractive, eye grabbing variegated foliage- the leaves are green with wide yellow margins; fragrant flowers that are a lavender pink color; plant has upright growth habit; didn't perform as well as expected—substantial winter loss but surviving plants were stunning.
Salvia nemorosa 'New Dimension Blue'
Compact clumps of well-branched plants; deep blue/purple flowers on spikes borne above the foliage; interesting leaf texture; long blooming—from late spring through late fall.
Salvia nemorosa 'New Dimension Rose'
Compact clumps of well-branched plants; rose-pink flowers on spikes rising above the foliage; interesting leaf texture; long blooming—from May through late fall.
Leucanthemum superbum 'Banana Cream'
Evergreen, compact clumper with dark green foliage; attractive butter-yellow flowers that bloomed June to mid-August.
Veronica 'Hocus Pocus'
Plants formed uniform clumps of green foliage; attractive long, purple flower spikes; Plants are evergreen; flowered from May to July/August.
Panicum virgatum 'Cheyenne Sky'
Maintenance free; red to purple panicles form on dense, upright clumps of foliage; the blue-green leaves turn red in early summer; fall interest; good texture.
Rosa 'Sunrosa Red'
Disease resistant; low maintenance; small blossoms begin as coral colored buds; floriferous plant; mild fragrance.
Rosa 'Sunrosa Yellow'
Disease resistant; low maintenance; petite, fragrant blossoms; floriferous plant.
Scabiosa columbaria 'Mariposa Violet'
Died summer 2012. Double, deep purple flowers on sturdy stems; blooms are above foliage; compact plant habit; grey-green leaves.
Campanula 'Ringsabell Rose'
Pendent rose pink bell-shaped flowers on slender stems; flowers are nicely displayed above the green foliage; vigorous growth—takes over an area.
Coreopsis 'Mercury Rising'
Large, red colored flowers with a little yellow eye that don't fade in the sun and the heat; vigorous grower but compact; it forms an attractive well- branched mound; continuously blooming; plants are evergreen.
SuperNova primula mix
Shade garden; a mixture of clear, eye-catching colors (one color per plant): lavender, pink, red, violet-blue, white, or yellow, all with yellow centers; the flowers emerged in the center of wavy green leaves; low maintenance.