Taking carnation cuttings involves cutting at least 6 inches from the stem of a carnation with a sharp knife once it finishes blooming for the season. Cuttings should include at least three nodes and new leaves. According to SFGate, they should come from new growth for the year. Removing any leaves from the lower portion of the stem allows the plant to use its energy for growing new roots.
Rooting hormone encourages root growth. Gardeners apply it by dipping the end of the stem cut nearest the plant root into the hormone powder and tapping away the excess. Once the stem is treated, the gardener should push at least 3 inches of the stem into moist soil and place the plant and its container in a plastic bag to conserve moisture. When using large trays, gardeners water the plants from the bottom and keep them covered with a sheet of plastic to ensure they stay warm and moist.
The cuttings take several weeks to root. Once roots form, tugging on the stem meets resistance, indicating it is time to transfer each new plant to its own pot. Cuttings do best in a warm area out of direct sunlight. Once the danger of frost passes, the new carnation plants are ready to be planted in the garden.