To root a plant in water, cut a 3- to 6-inch stem from an established plant directly above a leaf node and then place the cutting into a container of fresh water. In general, plants that have thick stems and leaves propagate well when rooted in water.
Rooting a plant in water is one of many ways to propagate a plant, although not all vegetation adapts well to this method. Certain plants, such as coleus, African violets and impatiens, typically perform well if properly rooted using water.
Locate a length of the plant you wish to propagate, and remove an ample portion by cutting the specimen at an angle. The angle creates increased surface area along the cut, which allows the maximum amount of water to enter the plant. Remove any leaves that fall beneath the water line.
Use tap water in a clear, disinfected glass jar for optimal results. Place the submerged cuttings in partial sun in an area that isn't prone to extreme temperatures. Replace the water in the container if it becomes murky or when the water level drops. If the plant stem or any roots become brown, discard the cuttings and begin the process again.
When the cuttings produce healthy roots that are 2 to 3 inches long, the cutting is ready to be potted.