Although most flowers are beautiful to look at, not all flowers last very long when they are cut and placed in a vase or flower arrangement. Some flowers may last a few hours before they wilt, while others begin to decline immediately after they are harvested. However, there are some flowers that hold up well after they are cut, and look great for a week or more as long as the stem ends are immersed in water.
Cockscomb (Celosia cristata) is an unusual cut flower that grows to 4 feet tall and produces crests, or combs, of large velvety flowers that are very long lasting after they are cut. There are many improved varieties of celosia available in yellow, red or pink. All celosias are tolerant of the hottest growing conditions and produce an abundance of seed.
Globe amaranth (Gomphrena globosa) or Bachelor Button produces unusual ball-shaped flowers of violet, red or white. The flowers are borne atop wiry stems that are easy to arrange and the flowers are suitable for drying. Amaranth grows well in the field and tolerates heat, dry conditions and insects.
Zinnias (Zinnia elegans) are very popular cut flowers because they are available in so many colors and interesting textures. Some zinnia plants produce small button type flowers and others produce flowers as big as 4 inches across. Zinnias are tolerant of all types of soils and thrive in warm conditions that would cause other flowering plants to fade.
There was a time when sunflowers (Helianthus annuus) were left in the back of the garden to go to seed and become ragged. In recent years, new varieties have been produced that have clean dark or green centers and uniform petals of yellow, orange, or even red depending on the variety. They are called florist type sunflowers and the seed is widely available. If you intend to plant sunflowers after July fourth, be sure to purchase varieties that are "day-length neutral" which means they can grow tall while the day length shortens.
Snapdragons (Antirrhinum majus) are a good flower to grow in cooler climates and can be grown in the winter in the southern U.S., although the best flower production will be in the spring. Snapdragons produce one large floral spike with multiple blooms or they can be pinched back to provide multiple smaller stems. Some varieties of snapdragons are more suitable as bedding plants because they are low-growing, so be sure to purchase seed or plants that are the cutting types such as the "Rocket" series.
The gladiolus, or sword lilies are a popular cut flower and easy to grow. The inexpensive bulbs can be planted in the spring and flowers can be cut in as little as 10 weeks depending on growing conditions. They are available in single and double blooming varieties that flower in a rainbow of different colors. Cut at the base of the stem when three or four of the lower flowers are open. The rest of the flowers on the spike will continue to open once the stem end of the flower spike is placed in a vase of water.