Published Caption: Lucian Perkins/Washington Post
Coleus are easy to grow from stem cuttings, and cuttings that are grown indoors all winter are likely to be more healthy and vigorous next season than the aging donor plant.
Ray Rogers offers these tips in his book "Coleus."
• Though coleus will root in water, the cuttings do better in a potting mix such as peat moss amended with perlite and sand. Grow them in a small pot or in a flat container with cells.
• Water the donor plant thoroughly an hour before taking cuttings.
• Choose a healthy stem and make a 1- to 2-inch-long cutting that includes two pairs of leaves. Pull off the lower leaves, and cut the upper leaves in half to reduce water loss. If the stem has a growing tip, pinch it out just above the upper pair of leaves.
• The cuttings need high humidity until roots form in a week or so. If you can't mist them regularly through the day, cover them with plastic or glass, and keep them out of direct sunlight.
• Move the plants into bigger pots once the root systems are well established. Through the winter and early spring, the rooted cuttings will need temperatures of about 70 degrees; bright, indirect light; and even moisture. Winter root rot is common if temperatures are too cool and the soil kept too moist.
• In late spring, set the pots outside in a shaded, sheltered location, and bring them in at night. After a week, the plants can be set outside, either in pots or garden beds.