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that attained the greatest increase in fresh weight (pH 3) had the best keeping quality while fl owers that had little increase in fresh weight (pH 7) had the poorest keeping quality. It is no wonder that the fl owers at pH 3 lasted longer because they absorbed about 70 percent more water than stems held in water at pH 6. Additionally, blockage decreased nearly 75 percent over the same pH range. All these positive impacts of low pH were due to ability of water to be absorbed easier at low pH. But, there is another factor : bacterial growth. Bacterial growth in the vase or bucket solution lowers water absorption by blocking or partially blocking the base of the stem where water is absorbed. Bacteria in vase water has been related to scape (leafl ess stem) bending of Gerbera and reduced longevity in many other crops. One solution to controlling the growth of bacteria is reducing the pH; lowering solution pH strongly may inhibit bacterial growth. In other words, by lowering the pH, the growth of microbes is reduced, which helps keep the stems clear so more water can be absorbed. Commercial hydration and fl ower food solutions contain a buff er to lower water pH to the desirable range. One other factor that solution pH aff ects is the presence of minerals that become crystallized in the solution. For example, in water with a pH higher than 7, iron, if present, precipitates out of the solution and will clog the cut stems. In water with high amounts of iron and a pH higher than 7 will result in nearly complete blockage of the base of the stem by iron in three days. And, of course, the fl ower wilts due to lack of water absorption. e following characteristics of water are related to water absorption or ability of the water to be buff ered. To have the ideal pH for cut fl ower water absorption, it is necessary to lower water pH between 3.5 and 5. Most water sources have a pH above 6, so hydration solutions and fl ower foods contain an acidifying agent to lower the pH. e ease or diffi culty of buff ering water pH depends on the amount of calcium carbonate (chalk) in the water. Calcium carbonate is measured in units of concentration, such as parts per million (ppm) or mg/liter. An alkalinity/calcium carbonate level between 60 and 180 ppm is best. Water with this level of alkalinity is easily buff ered with the acidifi er contained in commercial hydration and fl ower food solutions. As the level of calcium carbonate rises, the pH is more diffi cult to buff er. 2. Hardness Water contains naturally dissolved calcium and magnesium. Hardness is a measure of the amount of calcium and magnesium (parts per million/ppm) in the water. Total hardness is the sum of the calcium and magnesium levels. Generally, hard water contains high alkalinity levels, making the water diffi cult to buff er. Water with high levels of hardness will require special treatments to remove the calcium and magnesium. While water softening systems will remove these minerals, they should not be used in the fl ower industry. Water softeners replace the calcium and magnesium with sodium, and sodium can be toxic to fl owers. e most eff ective methods for reducing hardness are either deionization or reverse osmosis. For high levels of hardness, it is best to contact FloraLife for assistance and recommendations (info@fl oralife.com; 843-538-3839; fl oralife.com). 3. Total Dissolved Solids (TDS) Another measure of water quality is the level of total inorganic salts and organic matter present in water. Flowers do poorly in water containing high levels of salts. As with hardness, if the water contains high TDS, it is best to contact FloraLife for assistance. Also, be aware that a couple of salts, such as fl uoride, can be harmful to fl owers. e following fl owers may exhibit leaf marginal burning from fl uoride at low levels: Gladiolus, Gerbera, Chrysanthemum, snapdragons and roses. And, some foliage potted plants, such as spider plant (Chlorophytum comosum), are highly sensitive to fl uoride. HAVE YOUR WATER TESTED e only way to determine the quality of the water in your store or other facility is to have it professionally analyzed. e results of your water test will guide decisions about treating the water to achieve optimal outcomes. In most locations, use of commercial fl ower hydration and fl ower food solutions will provide positive results and excellent vase life without additional modifi cations. Testing does provide you with peace of mind that your water, with the correct solutions and handling practices, will provide your customers Extra Features and Video Online FloristsReview.com R E A D O N L I N E 41

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