Coleus cuttings create potted plants for the patio
If you keep a coleus as a houseplant, you can start cuttings for transplanting to the garden if you need more plants.
I have some I've been growing all winter in pots on a south-facing windowsill. Use a sharp, clean knife or a pair of pruners to cut the stem just below a leaf node. Remove the lowest leaves, dip the cut end into a rooting hormone and insert it into some fresh, sterile potting soil.
The cuttings will also readily root by placing them in a glass of water. Transplant to a pot with growing medium once a small mass of roots has developed.
The plants will be ready to use in the garden by the middle of May when the danger of frost has passed. Gradually acclimate the coleus plants to the outside environment by increasing the time the plants are left outside over a period of a week or so. Be sure to avoid direct sun at first so the leaves do not burn; most coleus prefer growing in light shade.
• Prune houseplants as needed and start fertilizing them as they begin new growth. Rotate your houseplants so that each side receives an even amount of light for more uniform growth and a balanced shape.
As the sun strengthens, some plants, such as African violets, may need to be moved away from a south-facing window to avoid leaf scorch. Make a focused effort to remove any spent flowers, dead leaves or branches, and any yellowing leaves.
Remove dust from leaves with a kitchen sprayer or by gently wiping them off with a moist cloth. This is a good time to repot them if needed.
A white or yellowish crust near the drain holes of the pot or at the base of the pot indicates a buildup of salt from either fertilizer or a hard water source. Excess salt in the growing medium can damage plants. Symptoms of damage include brown leaf tips and margins.
Flush out the soil with a thorough drenching of water to get rid of the salt. It is best to do this outside or in the sink, as there will be a large amount of water coming out of the pot's drainage holes.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.