Arrange cut flowers in a vase of warm water, and add commercial floral preservative. Or, you can make your own preservative with one cup lemon-lime soda (regular, not sugar free), one cup water, and a half teaspoon of household bleach. The sugar in the soda provides energy for the flowers, and the bleach controls bacteria. If you need more liquid, just increase the amounts proportionately.
Change the water in the vase every couple of days. In mixed bouquets, some of the flowers may give off sap that is toxic to other varieties in the vase and shortens their vase life. Daffodils are one such flower. You can reduce this effect by frequently refreshing the water or keeping daffodils in a vase by themselves. When you change the water, recut about a half-inch off the bottom of flower stems. This helps ensure the conducting vessels don't get plugged.
If you are preparing to start seeds under grow lights or fluorescent shop lights indoors, check the tubes for signs of age. Tubes that have been used for two to three seasons probably have lost much of their intensity even though they look fine. Dark rings on the ends of the tubes signal they need to be replaced. If just setting up such tubes, try the slimmer and more energy efficient ones. Alternate ones giving off warm and cool colors to provide the best light.
By Charlie Nardozzi of the National Gardening Association and by Dr. Leonard Perry of the University of Vermont.