Robert E. Lyons
Professor and Director
Department of Horticultural Science
JC Raulston Arboretum
Horticultural Research Series No. 152
The Annual Trial Gardens at NC State University are located within the JC Raulston Arboretum, 4301 Beryl Road, in Raleigh. The Arboretum is an 8 acre site administered by the Department of Horticultural Science and located on latitude 35° 47'N, longitude 78° 42'W with an elevation of 400 feet.
Seedling and vegetatively derived plants were grown to transplant size in 2.5 inch by 2.2 inch containers, with most planted outdoors on 31 October 2000. The remaining selections were planted when transplant survival was determined to be optimized. Plant spacing in the trials was 10 inches x 12 inches (in-row x between-row spacing). Thirteen plants of each entry were used to evaluate the performance of the cultivars. A total of 221 cultivars were evaluated with the majority being pansies (97 cultivars). Beds were fertilized with a pre-plant incorporation of 18 lbs./1000 square feet of 10-10-10, and every 6 weeks thereafter with broadcast applications of 15.5-0-0 through March. No pesticide applications were made during evaluation in order to document the impact of pests, and no major pest or disease problems were noted throughout the trial period.
We also gratefully acknowledge the support by Fafard, Inc. (P.O. Box 26, Anderson, SC 29622) and the North Carolina Commercial Flowers Growers Association. The assistance of Ingram McCall, Brad Holland, Mitzi Hole, Valerie Tyson, and Chris Glenn is acknowledged with much appreciation!
We continue to refine the way we present the information within this report. It is also posted to our Web site should you wish additional copies:
The following information should better acquaint you with our new approaches as well as assist you with what they all mean. We hope this will provide even more useful information whether you are one of our growers, landscapers, or one of our participating seed companies.
Number of Weeks in Flower
We have always recorded which weeks each variety is in flower, but we are now showing you the total number of weeks in flower. This will give you an idea of whether a plant is best used for the whole season or as a "fill-in" for rotations and special occasions. Obviously, those species grown for foliage interest alone will score poorly in this column!
Plants were given a visual rating weekly by the same person beginning 22 November, 2000 (three weeks after planting) through 28 March, 2001. The 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), using 0.5 unit increments; a 0 rating indicated that all seven plants of the cultivar trial died.
Summaries of Weekly Ratings
In the past, we presented an "all season average" of the weekly ratings for each variety over the whole evaluation period and made judgements based on this statistic alone. Knowing that there are many species/cultivars which may do better in one part of the growing season than another, we now provide an "early season average" and "late season average" for each entry. The former is the average of the first 8 weeks of the evaluation period and the latter is only the following 8 weeks. This information may be useful in planning short term plantings with high impact as well as for studying temperature preferences, life cycle changes, and/or the impact of photoperiod on plant performance. The "number of weeks rated above 3" gives you an idea of how consistently throughout the evaluation period an entry is an exemplary performer.
Each of the statistics above appears in all the lists that follow:
Seed companies are the backbone of our trials and our thanks go out to this year's participants. They are acknowledged in our tables throughout this report by the abbreviations found below.
|SEED SOURCE ABBREVIATION||SEED SOURCE|
|AT||American Takii, Inc. 301 Natividad Rd., Salinas, CA 93906-1401|
|BALL||Ball Seed Co., P.O. Box 335, West Chicago, IL 60515|
|BEN||Ernst Benary of Amer., Inc., 1444 Larson St., Sycamore, IL 60178|
|BFP||BallFloraPlant, 622 Town Rd., W. Chicago, IL 60185|
|GRS||Grimes Seeds and Plants, 11335 Concord-Hambden, Concord, OH 44077|
|JOHNNYS||Johnny's Selected Seeds, Foss Hill Rd., Albion, ME 04910|
|NCSU||North Carolina State University, Dept. Hort. Science 27695-7609|
|PA||Pan American Seed, 1017 W. Roosevelt Rd., West Chicago, IL 60185|
|SAK||Sakata Seed America, Inc., P.O. Box 158, Wrens, GA 30833|
|SYN||Syngenta Seeds, Inc., 5300 Katrine Ave., Downers Grove, IL 60515|
We also gratefully acknowledge the support by Fafard, Inc. (P.O. Box 26, Anderson, SC 29622) and the North Carolina Commercial Flowers Growers Association.
The winter of 2000-2001 was characterized by an early start of prolonged and unusually cool temperatures leading up to the end of calendar year 2000. We feel that this had a "delaying" effect on successful plant establishment following transplanting. The following months turned milder and the average lows tended to exceed the historical low temperatures for the months of January through April. Overall, this tended to allow many of the plants to come back from the damage incurred by the early, colder November and December. Winter precipitation levels were consistently lower than average, across the entire evaluation period. While this may have had some impact on plant performance, it was probably less noticeable given the initial lower temperatures in the early months.
The average minimum and maximum temperatures for the trial months of November and December, 2000, and January - April, 2001, in Raleigh, North Carolina. The historic minimums and maximums represent the 30 year period from 1961 - 1990.
Total precipitation for the trial period November and December, 2000 and January through April 2001, in Raleigh, North Carolina. The historic mean represents an average total precipitation from the years 1950 through 1995.
Weather Notes of Interest During Winter Trials
In this section you'll find summarized comments from those we recorded throughout the growing season......kind of like a "between the lines" addition to the actual ratings found in this report. Our comments do not necessarily include ALL of our species tested........just those we thought to be noteworthy in some way!
Ornamental Kale and Cabbages
These plants were adversely damaged by the onset of early cold temperatures. Most of them "melted" down to the ground after some hard freezes. However, many bounced back once the weather warmed up again....but the standout was the Red Bor Kale. This cultivar was truly outstanding as it deepened in color throughout the winter. It deserves wider use in the landscape and was the top scoring performer in ALL of our lists......not accomplished by any plant before in our trials. Of the more traditional kales, 'Flamingo Plumes' once again performed beautifully. The 'Osaka Red' cabbage was a similar standout. In fact, our "early season Leaders of the Pack" list was composed ENTIRELY of ornamental kales and cabbages!
Admittedly, we probably didn't give these plants a completely fair trial. By placing them in full sun, rather than in an area with some shade, I'm afraid they were faced with the stress of the unusual cold and excessive light. In fact, extra plants were grown in the home shade garden of one of our volunteers and they performed much better, surviving into the spring and flowering well. We will place all future Primula trials under some shade for a more fair evaluation.
Just not ready for prime time in our zone yet.......these plants grew and flowered poorly throughout the evaluation period.
Take our numbers with a grain of salt this time.......I think verbenas have potential but ours were planted a little later than the remainder of the trials and were caught by the early cold temperatures before becoming well established. This seemed to set the tone for the rest of the season, leaving us unimpressed but not indifferent to trying them again!
Snaps struggled.....never in flower and at best approaching only a "2" rating in the "early season", its best season! They survived, they just didn't thrive.
While nothing stellar for any of the overall performance averages, it is important to view the flowering data here. This group continues to insure a solid season of color in the landscape, with the series' averages showing a 7 - 10 weeks in flower. The best series was Sakata's 'Dynamite' which averaged over 10 weeks in flower....a great performance given our unusually cold season.
Sooner or later this group will not only be "discovered" but also adopted on the same widespread scale as pansies for landscape use in winter, especially if one views this data. Of ALL the different species examined this winter, virtually none flowered as notably as the violas. The 'Babyface', 'Penny', and 'Sorbet' series flowered for more than 15 weeks on average.....excellent! Their flowers may be smaller, but there is not shortage of them!
I'm grouping many miscellaneous species in this group which are related to lettuce, mustards and chard. The 'Southern Giant' mustard was worth a mention.....its tall, coarse and broad leaves made a real impact in the trials.....the plants performed fairly, but still worth a look, being rated at a 2.6 overall and 2.9 for later season only.
Although a wonderful early season bloomer, the obligate photoperiodicity (long days) has this plant flowering way too late for practical purposes.