Propagation is the reproduction of plants. Asexual or vegetative propagation uses only a part of a plant, like the stem, to root a new plant. Coleus and geraniums root easily from stem cuttings taken from the parent plant. However, coleus tends to take approximately ten days, while geraniums root in a month. Make sure to label your cuttings with the plant name and date, and put the whole box in a sunny location. Water the cuttings regularly, and don’t let them dry out.
Make a special rooting mixture of three parts sand and one part perlite. Use coarse sand or builder’s sand, available at garden-supply and home centers. Beach sand and play sand are too fine to use in a rooting mixture.
You will need:
- Solenostemon scutellarioides (coleus plant)
- Planting tray
- Coarse sand
- Pencil or bamboo stake
- Single-edged razor blade
- Rooting hormone
Propagating Coleus How-To
- Fill a wooden box or planting tray with rooting medium—a mixture of 2 parts coarse sand and 1 part perlite. This porous medium makes it easy for roots to form. Gently pack the medium with a brick, and then etch narrow trenches for the cuttings with a pencil (you could also use a bamboo stake).
- Using a clean, new single-edged razor blade, carefully cut off a 2-inch piece of coleus or geranium that includes stem and leaves. (A razor blade makes a cleaner cut than pruners and does not bruise the plant’s delicate tissues.)
- Remove all the leaves but the top 2 by carefully snapping them off by hand; pull down and away from the stem. Dip the tip of the stem in water and then into a rooting hormone. Place the cutting in the planting medium at a depth of 1/2-inch; space cuttings about 1/2 inch apart. The more you place in the planting tray, the more vigorously they will root because they like the competition. Water well, and make sure to keep the cuttings moist during rooting.