Carnations (Dianthus caryophyllus) are popular for their ease of care, beauty, fragrance and the fact that they make long-lasting cut flowers. They are, in fact, the most popular cut flower in the United States, according to Dr. Leonard Perry, a professor at the University of Vermont. Hardy in USDA growing zones 3 through 9, they can grow up to 20 inches tall, depending on the variety. These perennials come in a wide range of colors and bloom all summer long with proper care.
Plant carnations in the right location. These plants need full sun in order to bloom properly. They should receive a minimum of five hours of sunlight daily. Consider the climate as well. Carnations need cool weather in order to flower, so they are best grown in temperate zones. In addition, they are vulnerable to heavy winds, so plant them in a sheltered area.
Plant carnations in the fall, so their roots can become established before spring blooming. Plant carnations in holes as deep and wide as the root balls of the young plants, making sure they are between 10 to 15 inches apart.
Maintain the soil. Carnations need soil that is rich and well-draining but does not accumulate standing water, which can quickly rot the roots of the plant. Soil that is slightly moist is perfect. Mulch around your carnation plant to maintain the moisture in the soil and prevent weed growth.
Feed your carnations once a month during the summer with a balanced (10-10-10), water-soluble fertilizer. Do this in place of your regular watering, which should be once a week or more if the weather is very hot and dry. Carnations need watering when the top layer (down to an inch) of the soil becomes dry.
Deadhead your carnations to encourage more blooming. Pinch off the wilted blooms or cut them off the stems, but only remove a small portion (about 1/4 of an inch) of the stem with the flower head.
Cut carnations back almost to the ground in the fall when the foliage has begun to wilt, and add fresh mulch around the plant. The mulch will help it overwinter successfully.