Growing The Home Garden states that coleus is one of the easiest plants to propagate. The process is simple and straightforward, making it an ideal choice for the novice gardener, and the plants produce beautiful foliage in a variety of colors. You need a healthy coleus plant, a jar, water and potting soil.
Take a cutting from an established plant
Snip a cutting from a healthy, established coleus plant that has two leaves and about 2 inches of plant stem. Pinch the terminal growth end.
Allow the cutting to produce roots
Fill a glass jar partially full of water. Place the end of the cutting from the coleus into the water. Submerge most of the plant stem, but do not allow the water to touch the two leaves. Leave the cutting in the jar of water, and replenish the water level as needed. Do not add any rooting hormone. A healthy root system emerges from the cutting in less than a week.
Plant the cutting
Plant the cutting in a pot with potting soil, or in the garden in suitable climates, as soon as the roots have established. Make sure to keep the soil of the new coleus plant evenly moist.