During the summer of 2004, nine species of field-grown cut flowers  were evaluated for vase life and consumer preference.  Flowers were placed in the greenhouse headhouse   (70-85F) and in a lighted cooler (42F), with and without Floralife, a floral preservative.  All flowers were grown at the W.D. Holley Plant Environmental Research Center at Colorado State University, Fort Collins.
Flower varieties evaluated for vase life included New England and China asters, calendula, sweet William, eryngium, sunflower, rudbeckia, scabiosa and zinnia.
We found that Floralife increased the vase life of China aster, dianthus, helianthus, rudbeckia and zinnia, in both temperatures (Table 1), but did not improve the vase life of centaurea or eryngium.  And, surprisingly, in our trials Floralife  reduced the vase life of aster and calendula.
Cooler storage extended vase life much longer than floral preservative for all species. Mean vase life of nine species at room temperature varied from less than 5 days for calendula to 9 days or more for aster, callistephus, eryngium and rudbeckia.  The cooler greatly extended vase life for all species with a range of 13 days for zinnia to 52 days for callistephus and eryngium.  

Consumer Preferences

A public evaluation was conducted in 2004 to determine the marketability of eighteen cut flower varieties at the Colorado State University Greenhouse. Each variety was cut to the same length and placed in identical vases with the same number of stems. All varieties were rated on a scale of 1-5. One meant they did not like the flower and 5 meant they loved it.  If a species had more than one variety, evaluators were asked to write in their favorite of the group.
Results from the marketing survey (bar graph) showed calendula had the highest preference rating with rudbeckia ‘Autumn Colors’ and ‘Prairie Sun’ close behind.

Table 1. Mean number of days for vase life longevity at room and cooler temperatures with and without Floralife® preservative. Floralife® increased the vase life of some species, and not for other species.

 Species Room Temp. Room Temp. Cooler Cooler 
  With Floralife Without Floralife With Floralife Without Floralife 
 Aster*  7.00 11.00 9.50 20.00
 Calendula* 2.87 3.20 25.77 32.02 
 Callistephus 11.46 9.03 54.91 52.33 
 Centaurea* 6.75 6.75 39.91 40.29 
 Dianthus 8.72 6.94 53.77 38.27 
 Eryngium*  10.00 10.16 41.66 52.50
 Helianthus 8.84 7.23 40.07 38.98 
 Rudbeckia 11.99 9.10 48.13 46.64 
 Zinnia 7.83 4.66 14.70 12.92 

*Indicates that there was no difference or preservative decreased the vase life of this species. All other species showed an improvement in number of days before senescence occurred.

Among the dianthus varieties, ‘White with Deep Red Ring’ was the clear-cut favorite. Perhaps the reason for the drastic difference was the colors of the other dianthus varieties were not as bright and distinctive. Zinnias ‘Giant Purple’, ‘Giant Scarlet’ and ‘Giant Yellow’ all have vibrant colors while ‘Oklahoma Mix’ has pastel colors and ’Giant Lime’ has a  unique but less intense color. Preferences for the rudbeckia varieties were not as different as the other species varieties.