Every year at North Carolina State University, the Horticultural Science department of the College of Agriculture and Life Sciences conducts vase-life studies on promising species and cultivars from the ASCFG Seed and Perennial Trials. Most recently, we tested the vase life of 25 such cut ﬂowers.
During our studies, we found that vase life was longest for most of the cut ﬂowers when they were placed into a holding solution (low-dose/low-sugar nutrient solution), and for some, the best results were obtained when we placed the ﬂowers into a hydrator (hydrating solution) before the holding solution.
Our testing over the years has shown that the vase life of Lisianthus/Eustoma is significantly increased when these ﬂowers are placed into holding solutions or receive both hydrator and holding treatments. Similarly, Hibiscus ‘Mahogany Splendor’, which has become a popular cut foliage despite issues with postharvest handling, responded very well to a hydration solution treatment after harvest, increasing its vase life by three to ﬁve days and reducing the chances the stems would wilt within the ﬁrst couple days.
WHAT ARE HYDRATING AND HOLDING SOLUTIONS?
Some of you may be asking, “What are hydrating solutions and holding solutions?” Cut ﬂower treatments can be categorized as hydrating, holding or vase solutions.
Hydrating solutions are meant to be administered to cut ﬂowers right after harvest and/or following a period of dry transport, prior to a holding solution, to facilitate water uptake. These solutions improve the ﬂow of liquids through the ﬂower stems by clearing air and natural compounds blocking stem cell passageways. They do not contain a carbohydrate (nutrient) source. Hydrating solutions are usually used for a short amount of time, such as four hours.
Holding solutions contain a carbohydrate source (sugar) to encourage bud opening and/or ﬂower longevity and are administered to cut ﬂowers for several hours up to approximately two days either by growers or wholesalers before the ﬂowers get to the end consumers.
Vase solutions (full-dose nutrient solutions) are generally used by ﬂorists in arrangement containers and by consumers when they place their ﬂower purchases in water. Vase solutions contain a higher concentration of carbohydrates than holding solutions. While we do not test the use of vase solutions in these studies, it would be safe to assume that those ﬂowers that perform better with a holding solution would likely last longer for your customers with a vase solution.
ONE MORE THING
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 evaluation temperature that is a bit cooler than a typical home in a Southern summer. These procedures are set up to provide a consistent environment so that anyone else should be able to repeat our work and get the same results. These factors, combined, typically add about one to three days to the vase life of some species and cultivars compared to what a grower would usually get. It is also important to note that these results do not replace in-house testing, as there are many on-farm factors that aﬀect vase life.
This project was supported by the Association of Specialty Cut Flower Growers Research (ASCFG) Foundation and numerous suppliers. This article ﬁrst appeared in the Winter 2018 edition of ASCFG’s The Cut Flower Quarterly magazine. See that issue for complete results.
Field-grown ﬂowers were harvested at the optimum stage of ﬂower development and placed into tap water (0.21 EC, 6.1 pH). Stems were sorted into four equal groups and placed in the treatments below for the speciﬁed time, then placed into vases of deionized water.
• Hydrator only (4 hours)
• Holding solution only (2 days)
• Hydrator for 4 hours followed by holding solution for 2 days
• Tap water only (as a control)
We used Floralife Hydraﬂor 100 as the hydration solution and Floralife Professional as the nutrient solution, both at the rates listed on the packaging. After treatment, stems were placed in tap water and held at 68 ± 2 oF under approximately 200 foot-candles of light for 12 hours per day. The vase life for each stem was recorded. Termination point was typically when 50 percent of the ﬂower(s)/ﬂorets on the stem were brown, wilted, drooped over, etc.
Antirrhinum (Snapdragon) Maryland Dark Orange’
Flowers treated with a holding solution displayed a slightly increased vase life to 10 days. Untreated ﬂowers had a vase life of 9 days.
Dianthus barbatus ‘Magenta Bicolor’
Flowers treated with both hydrator and holding solutions had the longest vase life of 15 days, followed by the untreated ﬂowers at 14 days, and ﬂowers treated with only a hydrator at 12 days.
Helianthus annuus ‘EH16-10’
Flowers treated with only a holding solution had a slightly longer vase life (14 days) than ﬂowers that received both treatments (13 days). Untreated ﬂowers lasted 12 days.
Hibiscus ‘Mahogany Splendor’
This cut foliage responded very well to treatment with a hydrator, which increased vase life to 18 days from only 13 to 15 days without a hydrator. Treating the stems with hydrator decreased the likelihood they would wilt within the ﬁrst couple of days. Interestingly, the stems started to root after about two weeks in the vase, which was too late, of course, to prevent the wilting that occurred after harvest.
Lisianthus/Eustoma ‘Rosanne 1 Black Pearl’
Flowers treated with both hydrator and holding solution had the longest average vase life (14 days) followed by ﬂowers treated only with a holding solution (13 days) or only with hydrator (12 days). Untreated ﬂowers had the shortest vase life (9 days).
Lisianthus/Eustoma ‘Rosanne 1 Green’
Flowers treated with both hydrator and holding solution had the longest average vase life of 16 days as compared to 12 days of ﬂowers without any treatments or just a hydrator.
By Cristian Loyolla; John Dole, Ph.D.; Ingram McCall; and Ben Bergmann, Ph.D.
Department of Horticultural Science, North Carolina State University