Hardy perennials also known as pinks, carnations (Dianthus spp.) display spicy-scented flowers in nearly every shade of red, pink, yellow and white. The flowers, which appear in late spring or summer, bloom atop sturdy, slender stems measuring 6 to 24 inches tall, depending on the variety. Carnations are suitable for growing in U.S. Department of Agriculture plant hardiness zones 2 through 10. Although carnations thrive with minimal care, pruning and other plant maintenance revives tired, leggy plants and keeps carnations healthy and disease-free.
Pinch the growing tips of young carnations with your fingernails two to three weeks after planting to prevent tall, spindly plants and to stimulate more blooms. Pinch about half the tip of each shoot, along with the top pair of small leaves, if present.
Trim up to 25 percent of the carnation plant's total stems if the plant is scraggly in spring or midsummer. This process, called heading back, involves cutting the stems 1/4 to 1/2 inch above a lateral bud, which is a bud growing on the sides of the stem. Don't head back all the stems at the same height. Instead, make the cut above any lateral bud on the stem, staggering the height of the stems to create a natural-looking plant. Heading back the plant creates sideways growth, sturdy stems, a bushy, compact plant and often results in larger flowers.
Clip or pinch wilted carnation flowers throughout the blooming season. Remove the spent bloom, along with the stem down to the next leaf or bud. This process, known as deadheading, stimulates further blooming and helps to prevent legginess.
Cut back carnations after flowering ends in late summer or before new growth emerges in early spring. Use hedge shears or pruners to cut the stems to within 2 inches from the ground.