Dianthus caryophyllus, commonly known as the carnation, is one of many flowers that can be propagated through stem cuttings. If you have a particularly beautiful, healthy carnation plant, you can use its stems to create clones. Planting from seeds, on the other hand, will have unpredictable results. For example, seeds from a plant with lavender blooms might produce a plant with orange, pink, red or white blooms, but a plant grown from a stem cutting will always produce lavender flowers.
Cut a stem from a mature carnation plant at the end of the flowering season. Pick a stem growing from the base of the plant. The stem should be 6 inches long and have at least two to three nodes, which are the little bumps from which leaves grow. Sterilize a pair of garden shears with rubbing alcohol or a solution made with 9 parts water and 1 part bleach. Cut the stem at a 45-degree angle directly below one of the nodes.
Combine equal parts of peat moss and vermiculite or perlite to make a rooting medium. You can also use just plain peat moss. Fill a 6- to 10-inch planting pot with the rooting medium. Poke your finger into the medium to a depth of about 3 inches.
Pull off any leaves from all of the nodes except for the top two. Dip the stem into a glass of water and then into the rooting hormone so that the cut end, including the bottom node, is coated in the white powder.
Plant the stem in the hole you made earlier. Water the pot gently so that the soil is moist all the way through. Place the pot in a plastic bag and tie off the top. Tie it loosely so that air can still circulate through the bag. Place the pot in a warm spot in indirect sunlight.
Water the stem any time the soil looks a bit dry. Don’t let the soil dry out completely or the stem won’t root. Use a spray bottle to water the plant so you don’t disturb the rooting hormone before it has a chance to take effect. Remove the bag after about two to three weeks.