How to propagate a coleus houseplant
If you have kept a coleus over winter in your home, you can start cuttings for transplanting to the garden.
Coleus will develop a spindly growth habit when grown in too low of light, which is typical for coleus grown in a home. 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.
• When pruning large limbs off trees, it is a good idea to make an undercut on the branch first. This is a cut from the bottom up, about one-third of the way through the limb, 4 inches or so away from the main trunk. Make the next cut from the top, an inch or so outside of the undercut to remove the limb.
The undercut keeps the limb from splitting and breaking off, which could damage the trunk. Do not cut flush to the trunk, but just outside the branch collar at the base of the branch. Look for the point where the branch is enlarged close to the main trunk of the tree.
It is generally not recommended to paint the wound; make the cut with a sharp saw at the proper point for best results.
• Raspberries can grow into a tangled mess and produce poorly if not pruned properly. Prune fall-fruiting raspberries (fruit between August and October) back to the ground now to produce one crop of fruit.
Most autumn fruiting varieties are primocanes that produce fruit in their first year of growth. Cut the old canes as close to the ground as possible so that buds will break from below the surface of the soil. New canes will grow and set fruit later in the year. If the canes are not cut low enough, fruiting laterals may form on any remaining cane portion. These fruiting laterals will not be as healthy.
Summer fruiting varieties are usually floricanes, which fruit in the second year of growth; thus, 1-year-old stems should not be pruned back.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.