HAVE YOU or someone you know received cut

Transcription

1 Caring for Fresh Cut Flowers and Foliage AVE YOU or someone you know received cut flowers that died in a matter of days? It is disappointing to see flowers quickly die. ave you asked why they declined rapidly or what you could have done to make them live longer? This unit will address the care of cut flowers. Objective: Examine the care of fresh cut flowers and foliage. Key Terms: acidic alkaline bent necks conditioning ethylene inhibitors floral preservatives graded hard water hardened precooled salinity senescence soft water stem blockage transpiration turgid vase life Proper Care Fresh cut flowers and foliage are living things though they have been removed from plants. owever, once they have been removed, they begin to decline and die. Two needs for extending the life of cut flowers and foliage are water and sugar. A flower is 90 percent water. Plant cells filled with water are said to be turgid. Even after fresh flowers have been removed from plants, they continue with life processes, such as photosynthetic and cellular respiration. These processes require the use of water. The quality of water is extremely important for cut flowers. The p of water is a critical factor that determines water quality. A p test of the water can be conducted to determine whether water is acidic or alkaline. An acidic p has a reading below 7. p readings above 7 Page 1

2 indicate an alkaline solution. Slightly acidic water improves water uptake by fresh cut flowers and foliage. Floral preservatives added to water increase the acidity, thereby increasing water uptake. Water is classified as either hard water, which contains a high level of minerals, or soft water, which has been treated to lower the mineral level. ard water has a high p and is highly buffered, meaning it is resistant to a change in p. Softened water has been treated with salts to remove dissolved minerals. The addition of salts to the water lowers the water quality for flowers. Salinity is the measurement of total dissolved salts in water. Salts clog the xylem of the floral stem, preventing water movement and resulting in wilting and weakening of the stem. Salinity needs to be less than 200 ppm. Sugars are the food source for cut flowers. The two most common sugars are sucrose and dextrose. A flower gets these sugars from stores in the flower tissues, through photosynthesis, or through supplemental sugars provided in a floral preservative. p = 4 Acidic p = 7 Neutral igher p = more hydrogen ions p = 12 Alkaline FIGURE 1. Adding floral preservatives will correct alkaline and neutral p. CONDITIONING Conditioning is the preparation of cut flowers and greens when they arrive at the design site. The conditioning process involves the cutting of stems, adequate solution uptake by the plant materials, and cooling. Cutting Stems Flower stems should be re-cut. Leaves should be removed from the stems so that no leaves will be submerged in the water solution. Solution Preparation Flowers should be placed in water that is approximately 100 to 110 F (38 to 43 C), or about the FIGURE 2. Condition flowers in warm preservative solution. Page 2

3 temperature of a warm bath. Warm water speeds uptake and contains less air than cold water. Allow the flowers to take up water at room temperature for several hours before placing them in a cooler. Cooling Once the flowers are full of water, they can be placed in a cooler that is 34 to 38 F(1 to 3 C). Floral coolers are better than refrigerators because they provide controlled humidity levels in addition to cooling. Flowers that have been conditioned are said to be hardened and ready for use in arranging. Conditioning Steps Conditioning plant materials includes the following steps: 1. Unpacked and inspect flowers upon receipt. A report should be made to the wholesaler of any problems or mistakes. 2. Prioritize the order of processing. Condition the wilt-prone and expensive flowers first. 3. Remove sleeves, ties, and any foliage that might contact water in a container. 4. Under warm water, re-cut all stems, removing 1 / 2 to 1 inch. Professional underwater cutting devices are recommended. 5. Use specific treatment solutions as needed. 6. Place flowers in floral preservative solution mixed at the proper concentration. Too high a concentration encourages bacterial growth; too low a concentration can cause toxicity. 7. Let the flowers remain at room temperature for two to three hours to increase water uptake. 8. Place the flowers in a cooler set at 34 to 38 F (1 to 3 C), with a high humidity level and constant light. Flowers with milky stems, such as poinsettias and poppies, should be treated by dipping them in boiling water for five seconds and then placing them in a floral preservative solution. An alternative method is exposing the cut FIGURE 3. A bent-neck rose is a common site. Page 3

4 end to a match flame without burning the stem or placing it in very warm floral preservative solution. Roses that have lost turgidity near the flower heads are called bent necks. They can be revived by re-cutting the stems under water and placing the entire stems in a warm preservative solution. FACTORS TAT AFFECT VASE LIFE Many factors contribute to the vase life of fresh cut flowers and foliage. Vase life is the length of time cut flowers and foliage live after they have been cut. Sanitation, senescence, wilting, harvesting, ethylene, and disease or damage are some of the factors. Sanitation An important factor in the handling of cut flowers and greens is sanitation. Sanitation, or cleanliness, improves the vase life of flowers. ands, tools, knives, shears, containers, and work areas need to be kept sanitary. Introduction of bacteria and organisms can be avoided by cleaning work areas, coolers, and containers regularly. Senescence As soon as a flower is cut from the mother plant, it begins to deteriorate. This is partly because the flower no longer has a water or food source. The flower will eventually die. The decline is referred to as senescence. Senescence is influenced by genetics, lack of water, time of harvest, ethylene, and disease or damage. The life of each flower is based on its genetics. The natural lives of flowers differ between species. The flowers of the daylily live just 1 day. Dutch irises live 3 to 5 days, and roses 5 to 7 UNDER INVESTIGATION LAB CONNECTION: Floral Preservatives Floral preservatives are used to extend the life of cut flowers. Floral preservatives used in the trade have three main ingredients: a sugar, an acidifier, and a bactericide. Over the years many materials have been considered by some people to be effective floral preservatives. Some of these are aspirin, pennies, and Coca-Cola. Perhaps you have heard of others. You can design your own experiment to determine the effectiveness of these treatments in comparison to a commercial preservative. Prepare bud vases with different treatments you would like to test, including one commercial preservative. Label the vases with the names of the treatments, and place fresh cut flowers from the same bunch in each vase. Set the vases aside. Observe the flowers daily. Which treatments were the most effective? Which were the least effective? Page 4

5 days. Carnations last 10 to 14 days, and chrysanthemums 14 to 21 days. The goal is to obtain the maximum life of each flower as allowed by nature. Wilting Wilting is caused by the inability of plant tissues to absorb enough water to replace water lost by transpiration. The rate of transpiration increases in warm environments with low humidity. Transpiration can be reduced by keeping plant materials from drafts and avoiding overhandling flowers. Blocked vascular tissue can restrict the movement of water within a plant and cause wilting. Stem blockage is the most common cause of poor absorption. The xylem becomes clogged, and movement of water through the stem is restricted. arvesting The timing of flower harvest influences flower life. The time of day when flowers are cut is important. Flowers should never be cut when they are wilted. Therefore, avoid cutting in the heat of the day. Evening is the best time, because plants have been making sugars throughout the day. Morning is the second best time, because plants are full of water. The stage of flowering should be considered. The best time to harvest is just before a flower is fully open. Exceptions to the rule include the daisy and flowering bulb crops, which are harvested in bud stage, and the calla lily, which will not develop further once it is cut. FIGURE 4. Most flowers are harvested just before the flowers are fully open. Ethylene Ethylene gas promotes senescence. Ethylene gas is a natural plant hormone produced by aging flowers, foliage, fruits, and vegetables. Common signs of ethylene exposure include large numbers of fallen petals, dropped florets, and yellowing leaves. Fresh cut FIGURE 5. Ethylene damage on chrysanthemums. Page 5

6 flowers should be placed in an environment free of ethylene gas. Growers and wholesalers prevent this damage by using ethylene inhibitors, which are products that block or tie up the gas. Growers and wholesalers also strive to keep storage areas free of aging, decaying plant materials. Fruit should not be stored in a floral cooler because it produces ethylene gas. Disease or Damage Disease or damage shortens the life of floral materials. Flowers that arrive from the market and those picked in the garden should be of the highest quality. They must be inspected for disease and insect damage. FLORAL PRESERVATIVES Floral preservatives extend the life of cut flowers. A preservative contains a sugar as a supplemental food source, an acidifier to decrease the chance of stem clogging, and a bactericide to kill bacteria in a vase or stem. Pre-treatments are used before preservatives to reduce ethylene exposure and to hydrate flowers that are wilt prone, such as gerberas and roses. All flowers can benefit from a hydrating solution treatment. PACKING AND SIPPING The majority of cut flowers sold in the United States are produced in foreign countries. The commercial packing and shipping process affects the life spans of cut flowers in the floral market. First, flowers are graded, or separated into groups based on factors such as quality, uniformity, and size. They are also graded by stem quality, length, and strength. The flowers are then placed in bundles and sleeved for shipping. Delicate flowers, such as Fuji mums and gerberas, are individually sleeved. After bundling, the flowers are boxed for shipment and precooled, which is a method of quickly replacing the warm air inside the box with cool air. This process is also called dry packing. More delicate flowers, such as snapdragons and gladioli, are packed in hampers and stored in an upright position. Most flowers are shipped via air and then via truck to the marketplace. Summary: Two needs for maintaining the health of cut flowers and foliage are water and sugar. Slightly acidic water improves water uptake. Sugars come from stores in the flower tissues, through photosynthesis, or through supplemental sugars provided in a floral preservative. Page 6

7 Conditioning is the preparation of cut flowers and greens before arranging. The conditioning process involves the cutting of stems, adequate solution uptake by the plant materials, and cooling. Vase life is the length of time cut flowers and foliage live after they have been cut. It is influenced by sanitation, senescence, wilting, harvesting, ethylene, and disease or damage. Floral preservatives extend the life of cut flowers. A preservative contains a sugar, an acidifier, and a bactericide. The commercial packing and shipping process affects the life spans of cut flowers in the floral market. Flowers are graded, bundled, and sleeved for shipping. The flowers are boxed for shipment and precooled. Checking Your Knowledge: 1. What do cut flowers need to stay healthy? 2. What is conditioning? 3. What influences vase life? 4. ow do floral preservatives maintain vase life? 5. ow are flowers packaged and shipped? Expanding Your Knowledge: Condition flowers received in the classroom before they are used for arranging. Practice the conditioning procedure presented in this unit. Web Links: Cut Flowers and Florist Greens Conditioning Conditioning and Storing Cut Flowers and Greens (PowerPoint presentation) /care%2520and%2520handling.ppt+conditioning+flowers&hl=en&gl =us&ct=clnk&cd=8 Page 7