The life of cut flowers can be extended by treating the stems properly when they are harvested. Keeping them away from intense heat, sunlight or drafts will also make a big difference in their longevity. it is best to use distilled water to hydrate your cut flowers. Hard water may have too many minerals and soft water too few. You can distill water by filling a vessel and letting it stand overnight. Use all but the last 2 inches of the water. You can also buy distilled water in gallon jugs.
When to Cut Flowers
The best time of the day to cut flowers is in the morning. Moisture is lost from the petals and foliage in the afternoon sun. It is best to choose blooms that are just beginning to open. Fully opened flowers will decline and drop their petals very quickly. Use a sharp knife or garden shears to cut flower stems. Blunt cuts will damage the cell walls and impair water uptake. Stems also draw water better when they are cut at a slant. Crush woody or fibrous stems at the tip so they can take in water.
Keep Flowers Hydrated
If you purchase cut flowers get them into water as soon as possible. Cut the ends to open up the capillaries. If you are cutting your own flowers take a vessel of water to the garden with you. Place the flowers in the water immediately after they are cut. Remove any leaves that will be below the surface of the water. Bacteria will develop in the water as the leaves decompose.
Place all cut flowers in warm water the first day. You can use cool water the next time you change the water. Some types of flowers are prone to stem clogging and need to be re-cut more often. If they seem to wilt in spite of proper treatment, this could be the problem.
Commercial flower food contains three ingredients. It contains sugar to feed the flower, acid to increase water PH, and an anti-bacterial to keep the water fresh. A teaspoon of table sugar is all you need to feed a vase of flowers.
Use a teaspoon of lemon juice, citric acid or vinegar to increase the waters acidity. Bleach is often recommended to deter bacteria but changing the water each day will do the same thing. You will need to feed the flowers each time you change the water.
Special Care Flowers
Some cut flowers need special care. Flowers that ooze sap when they are cut will have a short life unless treated. The end of the stem can be burned with a candle or dipped in boiling water. This seals off the stem and holds in the sap so the flower will remain hydrated. Daffodils fit this criteria but exude a sap that is toxic to other flowers.
Place daffodils in a vase alone overnight until the sap drains out. The next day they can be included in arrangements with other flowers. Some flowers have floppy stems that will not take in water. The only way to use these flowers is to cut the stem away. The only way to display them is in a bowl of water. Florists add wire stems for support and place the flowers in the refrigerator on a damp paper towel. They will not last as long as a flower that can draw in water.