John M. Dole and Erin Y. Possiel, North Carolina State University

This project was supported by the American Floral Endowment, ASCFG Research Foundation and numerous suppliers. The authors would like to thank Ingram McCall, Diane Mays, Beth Harden, and Tina Krug for growing the cut flowers and for assisting with the postharvest studies.

Each year we test a sampling of the new cultivars that are included in the ASCFG National Cut Flower Trials and, occasionally, other species that we are growing in our cut flower plots. This year we screened 14 new cut flower species/cultivars. The species with the longest vase life was Eucomis ‘Sparkling Burgundy’. This plant produces tall flower spikes are made up of small greenish white flowers on a burgundy colored stem. We have had this plant in the trials for three years now and the clumps keep getting bigger every year and this year we had enough stems to officially test the vase life. Interestingly, this species does best in just water, with a vase life of up to 43 days. The use of holding preservatives ‘reduced’ the vase life to 34 days, which, of course, is still much longer than the vase life of most flowers. Thus, eucomis could be used in arrangements with other flowers even with the use of floral preservatives. The use of a hydration solution resulted in a vase life of 19 days and the use of both hydration and holding solutions produced the shortest vase life of 11 days.

Other cultivars with a vase life longer than 14 days included Echinacea ‘Comet’, Lisianthus ‘ABC White’, Pepper ‘On The Top Round Red’, Physocarpus opulifolius ‘Diabolo’, and Rose Kolster cultivars. For the latter species, we tested the large red rose hips, which lasted 24 to 26 days. These cultivars make great cuts that can be harvested in the fall. The plants have been vigorous and easy to grow, producing large quantities of rose hips on long arching stems. The plants produce runners so place them in an area were they can be contained.

This year we had three sunflowers in the trials and they produced rather typical results – responding well to holding preservatives. ‘Solara’ had the longest vase life, 12 days, and ‘Sunrich Orange’ the shortest of the three at 10 days. ‘Premium Lemon’ was in the middle at 11 days. To put these cultivars in perspective, of the 14 sunflower cultivars we have tested over the last four years, most had a vase life using floral preservatives of 8 to 11 days. Only three have produced a vase life over 14 days long (again, using floral preservative): ‘Sunny’, ‘Terra Cotta’ and ‘Sunbright’.

This year we answered part of question that has been bothering us – how do our results compare to commercial situations? Because we have a limited number of stems, we put one stem per jar when testing the vase life. Of course, in commercial situations many stems are put (crammed, sometimes) into a bucket. Thus, we tested the effect of putting 1, 3, 5, or 10 stems in a jar. With sunflower ‘Sunbright’, the longest vase life was 15 days with one stem per jar. The remaining treatments all had a vase life of around 13 days. With zinnia ‘Benary Dark Red’, the effect was more dramatic, the vase life dropped from 15 days for 1 stem/jar to 11 days for 10 stems/jar. Thus, we can say that our testing method of putting one stem/jar adds two to several days onto the vase life.

The Details

Field grown flowers were harvested at the optimum stage of development into buckets of tap water. The stems were processed, sorted and placed in the following treatments:

• Hydrator only
• Holding preservative only
• Hydrator followed by holding preservative
• Distilled water only

Floralife Hydraflor 100 (hydrator) and Floralife Professional (holding) were used. Where appropriate, stems were treated in the Hydraflor 100 for 4 hours and those in the Floralife Professional were treated for 20 hours. After treatment, stems were placed in tap water at 68±4°F under approximately 200 ftc light for 12 hrs/day. We expect that similar products from other companies would provide similar results. Because of limited flower numbers we are not able to test all products at this stage of evaluation. For most species we test 15 stems per treatment but will occasionally use 11 to 14 stems per treatment if we do not have enough stems. In the case of Eustoma ‘ABC Lavender’ and Eustoma ‘ABC White’, however, we had only 8 and 6 stems per treatment, respectively.

The Fine Print

Our testing methods tend to produce the maximum vase life, which tells you the potential vase life of each species. We cut and process the stems rapidly, put one stem per jar, and use a postharvest temperature that is a little cooler than a typical home in the summer. These procedures were set up to provide a consistent environment so that anyone else should be able to repeat our work and get the same results. All of these factors typically add about one to several days to the vase life of some species compared to that of a typical cut flower producer. For example, flowers with a vase life of 6 to 8 days in testing would probably last 5 to 6 days for a typical grower and flowers lasting 15 to 18 days would probably last 10 to 14 days. We especially want to note that when many flowers are added together in a vase, it only takes one or two “dirty” flowers to reduce the vase life of everything in the bouquet.

For several cultivars, we also listed the minimum vase life. We harvest and test 40 to 60 stems per cultivar and present the average vase life. With some cultivars most of the stems died about the same time. However, with other cultivars the flowers were terminated over a long period – thus the vase life of some of the stems was much shorter than the average. In those cases, we have included a minimum vase life.

Our Results