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Evaluation of Petunia Cultivars as Bedding Plants for Florida1
R.O. Kelly, Z. Deng, and B. K. Harbaugh2The state of Florida has been an important region for the growing and testing of bedding plants. The USDA Floriculture Crops 2005 summary reports that bedding and garden plants accounted for 51 percent of the wholesale value ($2.61 billion) of all the floricultural crops reported in the United States, while Florida was ranked fifth among all the bedding plant producers in this country. Thirty-seven percent of all bedding and garden flat sales came from pansy/viola, impatiens and petunias. Petunia (Petunia ×hybrida) ranked third in value after pansy (Viola ×wittrockiana)/viola (Viola cornuta and V. ×williamsiana [name used by some seed companies]) and impatiens (Impatiens walleriana). Florida ranked second in the United States for the value of potted petunia flats in the United States in 2005 ($4.5 million). Parts of the southeastern United States, Asia, Europe, and Australia share a similar climate with central Florida. Thus, Florida has also been an important testing ground for new petunia cultivars and other bedding plants to be grown and marketed in those regions.
Figure 1. Petunia axillaris (large white petunia). By permission of Mr. Juan Carlos M. Papa, Ing. Agr. M.Sc., Instituto Nacional de Tecnología Agropecuaria, Argentina. Petunia is considered to be the first cultivated bedding plant. Breeding began in the 1800s using two South American species with white (P. axillaris) and purple flowers (P. integrifolia).
Figure 2. Petunia integrifolia var. integrifolia (violet-flower petunia). Photo Courtesy of White Flower Farm (original seed source: Longwood Gardens). Five major class divisions resulted from petunia breeding: grandiflora, floribunda, milliflora, multiflora, and spreading. The first consistently double flowers became available, and more flower colors were added, in the 1930s from open-pollinated plants. Flowers became larger with better growth habit and disease and weather resistance after World War II. Award-winning F1 hybrids, designated as floribundas, appeared in the 1950s by crossing the larger flowered but heat-sensitive grandifloras with the adverse weather-resistant multifloras (smaller, but more numerous flowers than grandiflora). The hybridization resulted in costly seed, but plants were superior to open-pollinated cultivars. New flower colors (red and yellow) and growth habits (spreading [covers a 3-4 foot area] and miniature [millifloras]) expanded the available choices. Economical production of F1 seed resulted from the use of petunia as a model for plant physiology research that produced important changes in plant breeding through the understanding of pollen sterility. These changes resulted in significant contributions to the further development of the bedding plant industry in the last half of the twentieth century.
There are over 360 cultivars of petunia available on the market today. Florida's climate has great appeal to visitors from colder regions; however, for many bedding plants such as petunia, the climate here, at times, can be harsh for the plants and ideal for their pests, if cultivars have not been selected for this climatic zone. Since many petunia cultivars are developed and tested in more temperate climates, will these cultivars perform well in Florida? We answered this question by evaluating and selecting the best performing petunias in Florida from eight trials conducted between Septenber 2000 and June 2006. In the early trials, we created classes based upon growth habit (spreading vs. normal), flower form (double vs. single), and flower color and color pattern (solid color vs. multicolored flower types such as star or picotee), and then selected the best performing cultivar (standard) from each class. In each subsequent trial, we compared these class "standards" with new, untested entries from the major seed companies in Europe, Japan, and the United States. Some new entries outperformed the standards and replaced them, while some standards continued to outperform the new entries. On occasion, an entire class would perform poorly, while another class might contain all good performers. Nevertheless, we chose one cultivar to represent each class for subsequent comparisons. This system of standards allowed us to continually upgrade performance without having to reevaluate large numbers of previously evaluated cultivars; however, if a cultivar was not selected for the standard, but was later improved through further breeding, it could be reevaluated. Some cultivars represented unique classes without comparison.
Field Trials and Evaluations
Each cultivar was planted in two fields. Each field had multiple plots (three or four) planted for each cultivar in different parts of the field to compensate for variations in soil pH and moisture and pest infestations that might occur within different parts of the field and cause differences in plant condition between plots. Each plot contained five or six plantsOne field was sprayed (as necessary, after scouting for pests) to simulate a commercial setting and to produce plants in the best possible condition for measuring plant height, width and flower diameter, recording earliness of flowering, and comparing cultivar foliage and flower quality. The other field was not sprayed to observe the effects of plant pests on foliage and flowers as they would appear in a homeowner's setting. Ratings were on a scale from 1 to 7 for both fields, with 7 being free from any flaw, such as lack of plant or flowering uniformity, color fading or variability, open gaps in the plants, stem splitting, or pest symptoms such as insect feeding scars, leaf spots or plant blights, as well as distortions, discolorations and stunting due to virus infestation; 4 was average, but still acceptable; 1 was poor and unacceptable. The ratings in both fields were taken three to four times during the season to show performance over the entire season, and then the ratings from both fields were combined and averaged to yield an overall performance rating, which was used to select each class standard.
Seed was sown in seeder trays (model P-Seed20; Landmark Plastic Corp., Akron, OH), covered with a light layer of course vermiculite to retain moisture, and germinated at 72-75°F in a growth room illuminated 24 hours a day with cool-white fluorescent tubes. Exposure to light (10 to 100 foot candles) improves petunia germination greatly. The soil mix (example: Vergro Container Mix A; Verlite Co. Inc., Tampa, FL) was kept saturated during germination (stage 1; water seen on surface). For pellet-seed, it is important to drench immediately after sowing to break down the hard coating. Immediately after germination, seedlings were transplanted into Todd planter flats (model 128; Speedling, Sun City, FL) and grown to mature, non-flowering plugs (production stage 4). Soluble liquid fertilizers (example: 15-2-20 Ca-Mg Excel®; Scotts Co., Maryville, OH) were applied at 50 to 250 ppm (0.7 to 3.3 oz./100 gal) twice weekly. The soil mix was kept wet (not saturated, feels wet) during cotyledons expansion (stem present; production stage: 2). From the time true leaves were visible to the transplant stage (production stages 3 and 4), we alternated wet/moist (dark black to medium brown;). Petunia roots (length: ½ inch or more) develop best when oxygen levels remain high. When seedlings were ready for field planting, roots had formed a firm plug.
To provide optimal conditions for growth, raised ground beds 32" l × 8" h of EauGallie fine sand (pH range = 6.2 to 6.8) were fumigated with a mixture of methyl bromide and chloropicrin and covered with white-on-black polyethylene film. Two weeks later, plugs were transplanted into these beds; one week after transplanting, slow-release fertilizers (example: Osmocote Plus® 15-9-12 [5-6 mo.] with micronutrients; The Scotts Co., Maryville, OH) were applied by hand to each plant on the soil surface approximately one inch from the plant stem under the plastic mulch.
Summary
From 2000 to 2006, we evaluated 125 cultivars from 10 seed companies. The following cultivars included those that were selected as class standards, unique cultivars without comparison (to date), and cultivars that belonged to the same class, but could not be evaluated together in the same trial. All these cultivars had an overall performance rating 5.5.Floribundas: 'Celebrity Chiffon Morn', 'Celebrity Mid-Blue', 'Celebrity White', 'Madness Magenta', and 'Madness Waterfall Mix'.
Grandifloras: 'Double Cascade Blue', 'Dreams Sky Blue', 'Dreams Burgundy Picotee', 'Dreams Wild Rose Mix', 'Eagle1 Blue Improved', 'Eagle White', 'Limbo Blue', 'Storm Blue1', 'Storm Lavender', 'Storm Violet', 'Ultra Pastel Pink', and 'Ultra Salmon'.
Millifloras: 'Fantasy Light Lavender' and 'Fantasy Mix'.
Multifloras: 'Hurrah Pink Chiffon', 'Primetime Violet Star', 'Symphony Rose Star', 'Symphony Blue', 'Symphony Light Blue', 'Symphony Pink', 'Symphony Red Picotee', 'Symphony Rose', 'Symphony Salmon', and 'Symphony White'.
Spreading, normal: 'Avalanche Pink', 'Avalanche Lavender', 'Avalanche Rose', 'Easy Wave Shell Pink', 'Explorer Blue', 'Explorer Purple', 'Opera Light Purple', 'Plush White', 'Ramblin' Lavender', 'Ramblin' Peach Glo', 'Ramblin' Pink', and 'Ramblin' Salmon Capri'.
Spreading, tall: 'Kahuna Violet', 'Kahuna White', 'Ramblin' Burgundy Chrome', 'Ramblin' Lilac Glo', 'Tidal Wave Cherry', 'Tidal Wave Hot Pink', 'Tidal Wave Purple', 'Wave Blue'.
1The Eagle series has been dropped for future distribution in the United States market; however, remaining seed stock will be sold in the United States. Europe and Asia will continue to sell and order new production of this seed. 'Storm Blue' will replace 'Eagle Blue Improved'.
Detailed performance data for these cultivars is presented in Table 1, and flower pictures for each selected cultivar within its class are provided (Table 2). These cultivars can provide Florida growers and gardeners a wide selection of petunias from which to choose for their landscaping needs. Florida-selected petunias, with their great diversity of color and form, as well as their relative freedom from pests, provide Florida growers and gardeners a wide selection of hardier plants for our climate.
Additional information
Visit the seed-propagated bedding plant variety trials at for detailed information on petunias and other bedding plants.Note
The information in this report is a summary of experimental results and does not provide recommendations for crop production. Where trade names are used, no discrimination is intended or endorsement implied.Table 1. Plant and flowering characteristics and performance ratings for outstanding petunia cultivars with the highest ratings values for their class in spring/early summer (Bradenton [2000-04] and Wimauma [2005-06] and winter/spring (Wimauma [2005-06]) Florida trials.
Cultivar
Seed Company
Trial year evaluated
Measurements (inches)
Days to First Flower1
Cultivar Quality
Pest symptoms
Overall performance
Plant height
Plant width
Flower dia.
Foliage
Flower
Arthro
Disease
Floribundas
Celebrity Chiffon Morn
Bodger
2002
9
21
2.5
55
5.0
5.0
6.8
5.9
5.6
Celebrity Mid-Blue
Bodger
2002
11
20
2.0
63
5.0
5.5
6.3
6.0
5.7
Celebrity White
Bodger
2002
10
20
2.4
68
4.8
4.7
6.8
5.9
5.6
Madness Magenta
Ball
2002
8
20
2.2
61
5.2
5.0
6.3
5.8
5.5
Madness Waterfall Mix
Ball
2002
9
20
2.2
61
5.3
5.5
6.7
5.2
5.7
Grandifloras
Double Cascade Blue
PanAmerican
2004
11
21
2.9
61
5.5
4.6
6.3
6.4
5.7
Dreams Sky Blue
PanAmerican
2004
12
20
2.8
54
4.4
5.7
6.4
6.2
5.7
Dreams Burgundy Picotee
PanAmerican
2004
9
18
2.8
54
6.1
5.4
6.5
6.5
6.2
Dreams Wild Rose Mix
PanAmerican
2001
6
15
2.3
44
5.1
4.7
6.5
5.7
5.5
Eagle2 Blue Improved
Sakata
2004
8
19
3.0
53
5.7
5.9
6.5
7.0
6.2
Eagle White
Sakata
2000
10
22
2.6
36
50.0
6.0
xxx3
xxx3
5.5
Limbo Blue
Hem Genetics
2005-06
8
14
3.2
51
5.4
5.4
6.1
5.3
5.6
Storm Blue
Goldsmith
2004
9
21
2.8
57
5.0
5.0
6.5
6.7
5.7
Storm Lavender
Goldsmith
2002
12
21
2.4
61
4.8
5.3
6.4
5.6
5.5
Storm Violet
Goldsmith
2003
7
16
3.0
68
4.8
6.3
6.9
6.4
6.1
Ultra Pastel Pink
Goldsmith
2003
7
14
2.8
71
5.0
5.2
7.0
6.8
6.0
Ultra Salmon
Goldsmith
2002
8
20
2.9
64
5.7
4.5
6.2
6.3
5.7
Millifloras
Fantasy Light Lavender
Goldsmith
2001
6
14
1.5
47
5.8
4.6
6.9
5.6
5.7
Fantasy Mix
Goldsmith
2002
6
13
1.5
55
5.0
4.7
6.7
6.4
5.7
Multifloras
Hurrah Pink Chiffon
Syngenta
2002
7
17
2.2
55
5.5
4.5
6.7
6.4
5.7
Primetime Violet Star
Goldsmith
2002
9
23
2.2
59
5.5
4.0
6.9
6.2
5.6
Symphony Rose Star
Takii
2003
6
17
2.1
72
5.7
5.7
6.9
6.9
6.3
Symphony Blue
Takii
2001
8
13
2.1
45
3.9
5.3
6.8
5.9
5.5
Symphony Light Blue
Takii
2003
4
8
1.7
73
4.5
4.8
7.0
7.0
5.8
Symphony Pink
Takii
2001
6
16
2.4
44
5.1
5.0
6.8
6.2
5.8
Symphony Red Picotee
Takii
2002
6
12
2.1
53
4.8
3.7
6.9
6.2
5.6
Symphony Rose
Takii
2001
7
13
2.4
48
4.8
5.7
6.4
5.9
5.7
Symphony Salmon
Takii
2001
6
13
2.0
41
5.2
4.6
6.9
5.8
5.7
Symphony White
Takii
2001
8
15
2.6
46
5.4
4.9
6.8
5.6
5.7
Spreading, normal
Avalanche Pink
Bodger
2001
5
23
2.3
49
5.4
4.2
6.8
5.8
5.5
Avalanche Lavender
Bodger
2002
4
17
2.2
65
6.0
5.2
6.8
6.0
5.9
Avalanche Rose
Bodger
2006
9
36
2.2
63
5.3
5.5
6.3
5.9
5.8
Easy Wave Shell Pink
PanAmerican
2002
5
21
2.2
54
6.7
5.5
6.9
6.4
6.3
Explorer Blue
Sakata
2002
4
20
2.1
68
4.3
5.5
6.5
6.2
5.5
Explorer Purple
Sakata
2002
4
23
2.2
64
6.3
5.2
6.6
5.9
6.0
Opera Light Purple
Takii
2002
4
24
2.1
71
6.5
5.0
6.6
6.3
6.1
Plush White
Syngenta
2006
8
27
2.3
56
5.3
5.8
6.8
5.8
5.9
Ramblin' Lavender
Goldsmith
2003
4
20
2.1
72
5.7
5.0
6.9
6.9
6.7
Ramblin' Peach Glo
Goldsmith
2002
4
17
2.1
58
6.0
5.0
7.0
5.8
6.0
Ramblin' Pink
Goldsmith
2006
9
30
1.9
68
6.2
6.0
6.2
6.0
6.1
Ramblin' Salmon Capri
Goldsmith
2005
6
19
2.1
45
5.2
5.3
6.4
5.3
5.5
Spreading, tall
Kahuna Violet
Syngenta
2002
11
25
1.8
53
6.0
7.0
6.7
5.7
6.3
Kahuna White
Syngenta
2001
11
30
2.7
54
6.5
5.9
6.8
6.4
6.4
Ramblin' Burgundy Chrome
Goldsmith
2002
5
21
2.0
6.5
6.0
5.2
6.2
5.5
5.6
Ramblin' Lilac Glo
Goldsmith
2002
7
21
2.4
57
5.5
5.3
6.7
6.1
5.9
Tidal Wave Cherry
Ball
2000
20
38
2.0
44
6.7
6.4
xxx3
xxx3
6.6
Tidal Wave Hot Pink
Ball
2000
20
39
2.0
40
6.2
6.1
xxx3
xxx3
6.1
Tidal Wave Purple
Ball
2003
12
27
2.0
71
5.8
6.0
7.0
6.5
6.4
Wave Blue
PanAmerican
2006
9
41
1.9
67
4.3
5.3
6.2
6.1
5.5
1First flower unfurled in the transplant flat before planting in the field (2000 trial): one observation/cultivar (64 plants/cultivar/flat) 2The eagle series has been dropped for future distribution in the United States Market; however, remaining seed stock will be sold in
the Unisted States. Europe and Asia will continue to sell and order new production of this seed. 'Storm Blue' will replace 'Eagel Blue
Ilmproved.
3No pest symptom data was collected for cultivars (2000 trial), because an unsprayed field was not planted.
Table 2a.. Digital images of petunia cultivars (organized by class1) with the highest overall performance rating values for their class in spring/early summer [Bradenton (2000-04) and Wimauma (2005-06)] and winter/spring [Wimauma (2005/06)] Florida trials.
Footnotes
1. This document is ENH 1078, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October, 2007. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.2. R.O. Kelly, coordinator/variety trial research; Z. Deng, assistant professor; and B.K. Harbaugh, professor, Environmental Horticulture, Gulf Coast Research and Education Center, Cooperative Extension Service, IFAS, University of Florida, Gainesville, 32611.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
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