Perennials Trial Report

North Carolina State University
Raleigh, North Carolina
2014–2015

JC Raulston Arboretum at
North Carolina State University
Raleigh, North Carolina

Mark Weathington
Director

Bernadette Clark
Agricultural Research Technician

Department of Horticultural Science
JC Raulston Arboretum

Table of Contents

General Introductory Notes and Acknowledgements
Understanding Our Data
Climate Graphs
Plant Material Sources
Results

General Introductory Notes and Acknowledgements

The Perennials Trial are located adjacent to the Color 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'.

Plants to be entered into our trials are received in one of three 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' × 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.

Acknowledgements

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!

Participants

2012

Foremostco, Inc.

2013

Ball Ingenuity
Kieft-Pro Seeds

2014

Dümmen Group (Bartels)
Syngenta Flowers
Walters Gardens, Inc.

We also thank the following companies for their support of material donations:

• BASF, 26 Davis Drive, Research Triangle Park, NC 27709
• Sun Gro Horticulture, 3723 Hogshead Road, Apopka, FL 32702

Understanding Our Data

Cultural Data

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"–1.5" 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.

Evaluations

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.

What do we look for?

• General Plant Growth – healthy appearance, attractive foliage, uniform growth
• Flowers – floriferousness, bloom duration, uniform color, does it hold up after a heavy rain
• Pests and diseases – any visible evidence of damage: distorted or chewed foliage
• Heat tolerance – do the flowers and plants hold up in the heat, does the flower color fade or stripe
• Hardiness (survival) – determined (in the spring) by the number of plants that made it through or emerged after the winter

Installation Date

Most entries were planted into their permanent trial location on:

• Rose entries were planted on September 25, 2012
• 2013 entries on May 21, 2013
• 2014 entries on May 13, 2014

Entries that Did Not Survive

Died 2013

Armeria pseudarmeria 'Ballerina Lilac' (Ballerina®™ mix)
Digitalis purpurea (Dalmatian Purple Improved)
Digitalis purpurea (Dalmation White Improved)
Primula polyanthus (SuperNova mix)
Heuchera 'Autumn Leaves'

Died 2014

Lavandula angustifolia 'Sweet Romance'
Nepeta 'Cat's Meow'
Phlox paniculata 'Early Dark Pink'
Phlox paniculata 'Early Purple'

Removed Entries

2014

Rosa 'KORjuwko' (Kolorscape® Milano) – rose rosette

The best way to really evaluate our trials is to come in person. The JCRA is open 365 days a year.

Average Monthly Precipitation and Temperature

Soggy is a good description of our summer. We experienced heavier than normal rainfall with many events of 1" or more, including one 4.5" and one 3.25" rainfall. Rain totals for the summer season exceeded the norm by 9.8". The petunias were the group that struggled the most under these conditions.

The temperatures for us this summer were pretty average, and our swings were moderate. The hottest temperature (97°F) occurred once in each month—June 19, July 9, August 21, and September 2. The longest stretch of days above 90°F was a run of six days in August. The total number of days at or above 90 was 50, roughly 30% of our growing period.

Our winter was much colder than normal with the second half of February being the coldest on record. In February, we had lows that bottomed out around 7°F, normally unheard of for our area. And, the season concluded with a late season blast (March 29, 2015) with a low of 22°F! Our precipitation in the first three months of the season was slightly above average but in the last three months there was a significant decrease. We ended the season with a precipitation deficit of 1.2".

Seed and Plant Material Sources

Ball Ingenuity, P.O. Box 335, West Chicago, IL 60185
Dümmen Group (Bartels), 15245 W. Telegraph Road, Santa Paula, CA 93060
Foremostco, Inc., 8457 NW 66th Street, Miami, FL 33166
Kieft-Pro-Seeds, P.O. Box 335, West Chicago, IL 60185
Syngenta Flowers, 6899 Winchester Circle, Suite 102, Boulder, CO 80301
Walters Gardens, Inc., 1992 96th Avenue, Zeeland, MI 49464

Please get in touch with these companies if you have specific questions regarding individual species and cultivars.

Trial Results

Perennials Planted in 2012

Rosa
Sunrosa® Red rose

Company

Foremostco

Year Planted

2012

Height

25"

Spread

21"

Number Planted

9

Survival

100%

Comments

Continues to be disease resistant; low maintenance; small, reddish colored blossoms cover the plant from May through mid-November; petite plants with attractive red colored new foliage; mild fragrance; Sunrosa series is the shortest of the rose series evaluated.

Rosa
Sunrosa® Yellow rose

Company

Foremostco

Year Planted

2012

Height

27"

Spread

21"

Number Planted

9

Survival

100%

Comments

Disease resistant, but less resistant to leaf spot than others evaluated; low maintenance; petite, yellow blossoms cover the plant from late April to mid-November; fragrant blossoms; Sunrosa series is the shortest of the rose series evaluated.

Perennials Planted in 2013

Rosa 'KORelfkolo'
Kolorscape™ Cheri rose

Company

Ball Ingenuity

Year Planted

2013

Height

32"

Spread

27"

Number Planted

5

Survival

80%

Comments

Removed one plant due to rose rosette. Dark green foliage on compact, upright plants; Forms many clusters of single, fragrant, bright pink flowers; great flower power, gives you non-stop color from early May through November (up until first hard freeze); good resistance to black spot; can be used as a cut flower and in small scale gardens; attracts bees; low maintenance.

Rosa 'KORjuwko'
Kolorscape™ Milano rose

Company

Ball Ingenuity

Year Planted

2013

Height

34"

Spread

22"

Number Planted

5

Survival

0%

Comments

Started flowering in mid-May and was still flowering when removed in early September due to rose rosette.

Rosaa 'KORhopiko'
Kolorscape™ Flamingo rose

Company

Ball Ingenuity

Year Planted

2013

Height

37"

Spread

24"

Number Planted

5

Survival

100%

Comments

Large, glossy green foliage on compact, upright plants; forms clusters of single, lightly fragrant, hot pink, flowers; great flower power, gives you non-stop color from May through November (up until first hard freeze); good resistance to black spot; can be used as a cut flower and in small scale gardens; attracts bees; low maintenance.

Rosa 'KORsixkono'
Kolorscape™ Kardinal rose

Company

Ball Ingenuity

Year Planted

2013

Height

32"

Spread

38"

Number Planted

5

Survival

100%

Comments

Large, glossy green foliage on compact, upright plants; forms clusters of single, lightly fragrant, clear red, flowers; great flower power, gives you non-stop color from May through November (up until first hard freeze); good resistance to black spot; can be used as a cut flower; attracts bees; low maintenance.

Perennials Planted in 2014

Hibiscus 'Cherry Cheesecake'
Summerific® hibiscus

Company

Walters Gardens, Inc.

Year Planted

2014

Height

38"

Spread

27"

Number Planted

5

Survival

100%

Comments

Large (7"–8"across), attractive flowers on compact (approximately 3' tall) plant; The flowers have a wavy look and are white with magenta veins; flowers from July to September; Hibiscus sawfly larvae ate the foliage.

Phlox paniculata 'Early Pink Dark Eye'
garden phlox

Company

Dümmen Group (Bartels)

Year Planted

2014

Height

8.5"

Spread

11"

Number Planted

9

Survival

56%

Comments

Low maintenance; compact clumps of green foliage; showy flower heads, nicely poised above the foliage; flowers are a light pink color with dark pink centers; great flower power; flowered from May into November.

Phlox paniculata 'Early Dark Pink'
garden phlox

Company

Dümmen Group (Bartels)

Year Planted

2014

Height

9.5"

Spread

9.5"

Number Planted

9

Survival

0%

Comments

Died winter 2014–15; low maintenance; compact clumps of green foliage; showy flower heads, nicely poised above the foliage; flowers are a dark pink color with dark pink centers; flowered from May into September.

Penstemon hartwegii
Arabesque™ Appleblossom scarlet beard tongue

Company

Syngenta Flowers

Year Planted

2014

Height

23"

Spread

9.5"

Number Planted

12

Survival

0%

Comments

Died winter 2014–15; our record breaking cold February may have killed the plants even though they were mulched; low maintenance plants form bushy clumps that are covered with sturdy spikes of flowers; the flower period is summer into the fall; the red and white bicolor flowers are trumpet shaped with a white throat; great for attracting butterflies.

Penstemon hartwegii
Arabesque™ Pink scarlet beard tongue

Company

Syngenta Flowers

Year Planted

2014

Height

15"

Spread

6.5"

Number Planted

12

Survival

0%

Comments

Died winter 2014–15; our record breaking cold February may have killed the plants even though they were mulched; low maintenance plants form bushy clumps that are covered with sturdy spikes of flowers; the flowering period is summer into the fall; the deep pink flowers are trumpet shaped with a white throat; great for attracting butterflies.

Penstemon hartwegii
Arabesque™ Red scarlet beard tongue

Company

Syngenta Flowers

Year Planted

2014

Height

17"

Spread

11"

Number Planted

12

Survival

0%

Comments

Died winter 2014–15; our record breaking cold February may have killed the plants even though they were mulched; low maintenance plants form bushy clumps that are covered with sturdy spikes of flowers; the flowering period is summer into the fall; the dark red flowers are trumpet shaped with a white throat; great for attracting butterflies.

Penstemon hartwegii
Arabesque™ Violet scarlet beard tongue

Company

Syngenta Flowers

Year Planted

2014

Height

18"

Spread

11"

Number Planted

12

Survival

0%

Comments

Died winter 2014–15; our record breaking cold February may have killed the plants even though they were mulched; low maintenance plants form bushy clumps that are covered with sturdy spikes of flowers; the flower period is summer into the fall; the bright violet colored flowers are trumpet shaped with a white throat; great for attracting butterflies.

Heuchera 'Inheuredfu'
Dolce® Cinnamon Curls™ coral bells

Company

Walters Gardens, Inc.

Year Planted

2014

Height

6"

Spread

8"

Number Planted

9

Survival

0%

Comments

Died by end of August 2014; the excessive rainfall we experienced was the culprit for the failure of this entry; the plants had beautiful curly leaves of an orange-red color.