The following article was reprinted with permission from George Staby, an expert in cut flower postharvest care. Dr. Staby hosts a web site, www.chainoflifenetwork.org, that offers extensive resources on cut flower care, including photographs, advice on when to harvest, special post harvest treatment, and expected vase life. It also offers articles on special topics, such as the one reprinted below. The web site is free to anyone who registers. We highly recommend it for all cut flower growers.

Most cut flowers benefit from flower foods, which normally contain from 0.6 to 0.9% sugar when made according to label directions. However, some flowers benefit more from higher sugar levels (2-20%) such as Baby’s-Breath, Gladiolus, Lisianthus, Tuberose, Bird-of-Paradise, and Brodiaea among others. How can high sugar-containing flower food solutions be made so they can be used to increase the quality, vaselife, and opening of these flowers?

First, it must be emphasized what not to do. Namely, do not add more flower food to water than label directions state in order to get higher sugar levels, as this will likely cause problems. Why? While it is true that you would be increasing the sugar levels, all of the other ingredients that are in the flower food will also increase. As a result, higher rates of these other ingredients may damage flowers and/or leaves.

The best way to increase sugar levels is to add more sugar to freshly prepared flower food solutions. In this way only the sugar levels are increased, but not any of the other flower food ingredients. Common table sugar sold at grocery stores can be used.

Information presented in the following table summarizes how to make solutions containing various sugar levels. Remember, this assumes that you are adding sugar to freshly made flower food solutions that already contain some sugar.

In closing, there are a few points to make regarding the use of high sugar flower food solutions:
•Sugar and labor are not cheap. Therefore, always run tests to determine the benefits and/or problems before establishing routine treatment procedures.
•Only treat flowers that benefit from high sugar treatments and only treat them for the time and at the temperature recommended. Longer treatment times and/or higher treatment temperatures may damage the flowers and/or leaves.
•Some of the flowers that can benefit from high sugar treatments include Baby’s-Breath, Gladiolus, Lisianthus, Tuberose, Bird-of-Paradise and Brodiaea. Consult the Floral Crop Specifics section of this website to learn the recommended sugar levels for these and other flowers.
•Always add sugar to a flower food solution, not to plain tap water, as flower foods contain other ingredients that will help improve flower performance.
•Using warm water will facilitate the mixing of the sugar, just like adding sugar to hot tea goes into solution faster than adding sugar to ice tea. Using warm water is especially important for the higher-level sugar solutions.