Should a person purchase flower preservative to make their flowers last longer, or will homemade solutions work just as well?
Researchers at the University of Florida have found that purchased floral preservatives work best at controlling microbial populations, hydrating stems, and feeding flowers. While some homemade solutions work, some may actually shorten the life of your flowers.
Various mixtures containing such ingredients as aspirin, gin, vodka, 7-Up, pennies, sugar, bleach, and other substances are sometimes recommended. In truth, some of these methods work, and some do not. A small amount of bleach will impede the growth of bacteria, but too much will damage flowers. Sugar will feed the flowers, but too much will increase microbial growth. Commercial mixtures have exactly the right amount of nutrients and antimicrobial agents to keep your flowers fresh for the longest possible time.
However, if you do not have access to a specially formulated floral preservative, Purdue University recommends any of the following mixtures.
Mixture # 1: 2 cups lemon-lime carbonated beverage, 2 cups water, and 1/2 teaspoon household chlorine bleach
Mixture # 2: 2 tablespoons fresh lemon juice, 1 tablespoon sugar, and 1/2 teaspoon household chlorine bleach, mixed with 1 quart water
Mixture # 3: 2 tablespoons white vinegar, 2 tablespoons sugar, and 1/2 teaspoon household chlorine bleach, mixed with 1 quart water (Please note that this author does not recommend this mixture as combining vinegar and bleach, even in small amounts, creates a very poisonous gas.)

ImageShould I remove the leaves from cut flowers, and should thorns be removed from roses?
Always remove any leaves that will be under water. However, researchers at the University of Florida recommend not removing any more above-water foliage than necessary. According to the researchers, transpiration of leaves causes water to flow up the stems of cut flowers, thus hydrating the flowers. Remove any above-water leaves that are damaged, but leave all healthy foliage intact.
Do not remove the thorns (prickles) from roses. Despite hearsay and opinions to the contrary, removing or dulling the prickles damages the stem and creates wounds that permit stem-clogging microbes easy access. Water travels most freely through an undamaged stem.

What other steps can I take to ensure the longest possible life for my cut flowers?
Bacterial growth is a primary enemy of cut flowers. Anything that can be done to maximize cleanliness should be first and foremost. It stands to reason that all cutting implements should be clean, as well as the vase or container that holds the flowers.
Other measures will also prove invaluable. Avoid placing your flowers near fruit. The ethylene gas produced by ripening fruit will also ripen your flowers. Keep cut flowers out of direct sunlight, and protect from drafts or air from heating and cooling vents that will cause them to desiccate. Remove flowers as they wilt, and change the water at least every two or three days. Each time water is changed, add more preservative to the water and recut the flower stems.

I grow my own flowers. What are some tips about cutting flowers from my garden? Image
Choose flowers that are newly opened or almost open. Plunge the stems in water immediately after cutting. Recut the stems under water as soon as you get them inside, and let them rest and condition in fresh water for at least a couple of hours. The best time to cut is in early morning before the dew has dried or late in the evening just after the sun has gone down and the flowers have spent the day manufacturing food. Make sure plants were watered well several hours before cutting.
As important as flower selection is the method of cutting. Flowers should be cut at an angle with a sharp blade. A sharp blade cuts cleanly without crushing plant tissues and inhibiting the uptake of water. The angled cut not only increases the surface area for water absorption, but also lifts the cut ends off the bottom of the container so nothing interferes with the free movement of water up the stem.

What are some particularly long-lasting flowers?
If you are purchasing flowers, be sure they are fresh. Check to see if any wilted flowers are in the bundle or if leaves are yellowing or browning. It does no good to follow all the prescribed practices if the flowers are already past their prime. Image
Chrysanthemums are favorites, and for good reason. They are among the most long-lasting of cut flowers. Chrysanthemums come in many shapes, sizes, and colors. Properly treated, they can last up to 20 days in a vase.
Carnations can last as well as chrysanthemums. Choose from mini carnations with several small flowers on a stem or large ones with a single flower on a stem. Carnations are available in a wide range of colors and bicolors.
Alstroemeria is also a popular cut flower that has proven its mettle. Although appearing to be delicate, they last up to 14 days. The trick, as with other flowers, is to be sure they are fresh when purchased.
Glads, statice, liatris, and lisianthus will last up to 10 days. The truth of the matter is that almost all flowers grown for the cut flower market are bred to last a long time after they are cut. If flowers purchased from a florist or supermarket are fresh at the time of purchase, you have a good chance of having a long-lasting bouquet provided care is taken to keep them fresh.

Do some types of flowers require special treatment?
Yes, they do. Lilies, for instance, open to reveal anthers covered with pollen. The pollen will fall to the surface of your furniture or table linens and stain them. As soon as lilies open, carefully remove the pollen-covered anther.
Flowers with milky latex, such as poinsettia, euphorbias, poppies, and hollyhock, exude a milky sap that will inhibit the uptake of water. Prevent this problem by dipping the bottom of the stems in boiling water for about half a minute, or hold over a flame of a lighter or gas stove eye.
Narcissi emit a slimy substance that is toxic to other flowers, so don’t place them in mixed bouquets.

Conclusion: Taking time to harden or condition cut flowers and practicing the prescribed procedures can definitely lengthen the life of cut flowers. Take the time to do it right and enjoy many long-lasting bouquets.