Water Temperature

Professional florists and commercial growers always use lukewarm water for their cut flowers. The water temperature should be 100°F to 110°F. (An exception is when you are using bulb flowers, such as hyacinths and tulips, which need cold water.) Warm water molecules move faster than cold water molecules and so can be absorbed by flowers with greater ease. The objective is to get water and nutrients as quickly as possible to the head of the flower.

Preservatives

Using a preservative definitely increases the longevity of cut flowers. To survive, flowers need three ingredients: carbohydrates, biocides, and acidifiers. Carbohydrates are necessary for cell metabolism; biocides combat bacteria and are necessary for maintaining plant health; acidifiers adjust the pH of water to facilitate and increase water uptake.

Homemade Flower Preservative

Home mixes can be as effective as commercial preservatives. This easy-to-make recipe is my favorite.

1 teaspoon sugar
1 teaspoon household bleach
2 teaspoons lemon or lime juice
1 quart lukewarm water

Under normal circumstances, flowers get what they need from the plant. When severed from the plant, however, flowers are deprived of these essential substances. But they are present in ready-made commercial preservatives, like Floral Life. Such solutions contain sugar for nutrition, bleach to keep the water clear of bacteria, and citric acid to gently acidify the water. When using commercial brands, be sure to follow recommended measurements for different container sizes. You can also make your own preservative .

One common suggestion is to place an aspirin in the water to keep flowers fresh. It is likely that aspirin's effectiveness is simply the result of the drug's carbohydrate content. Another well-known suggestion is to drop a penny into the water. Apparently, the copper in the penny works like an acidifier, decreasing the pH of the water. Unfortunately, solid copper pennies are no longer being minted.

Preparing the Stems

Garden flowers require some additional preparation after cutting. The type of preparation depends on the type of flower stem: hearty, hollow, soft, woody, or milky.

• Hearty Stems Flowers with hearty (or solid) stems, such as cockscomb, Clarkia, marigolds, statice, and transvaal daisies, need only the diagonal cut to absorb maximum water. They should be left to drink in lukewarm water with preservative for a minimum of one hour before arranging.

• Hollow Stems The stems of hollow-stemmed flowers, such as amaryllis, bells-of-Ireland, dahlias, delphiniums, and hollyhocks, need to be filled with water. Simply turn the flower upside down and pour water into the open cavity of the stalk. To keep the liquid in, you can plug the stem with a small piece of cotton and then place it in the vase. Alternatively, place your thumb over the opening at the bottom of the stem and then put it in the water. The water trapped inside will keep the stem strong and straight.

• Soft Stems Bulb flowers such as hyacinths, iris, and tulips have soft stems and should be cut where the green on the stem starts—just above the white bulb. Place the flowers in cold water. Since most bulbs bloom when the air and ground are still at low temperatures, they do better in a vase of cold water.

• Woody Stems For woody plants such as lilac, dogwood, mock orange, pear, and heather, be sure to split the stems at the ends rather than smash them. This will keep vascular tissues intact and create more surface area to absorb water.

• Milky Stems Flowers such as euphorbia, lobelia, poinsettia, and snow-on-the-mountain secrete latex sap that oozes into the water and clogs the vascular system of other flowers in the container, preventing them from absorbing water. For this reason, the ends of the stems need to be seared before the flowers are placed in the arrangement. There are two ways to accomplish this: Either dip the cut end of the flower in boiling water for 30 seconds or apply a flame from a match or candle to the precut flower stem for about 30 seconds.

Do not use these flowers with a pin holder, because each time the flowers are cut they need to be seared again. Searing is not effective in halting the seepage of secretion from daffodils. Therefore daffodils should not be mixed with other flowers if you want a long-lasting arrangement.