Stem cuttings can be propagated effectively in water or soil, and the best time to do it is in the spring. Water propagation in a clear jar makes it easy to see the developing root growth, which isn’t visible in soil, but both methods work well for propagating your plant.
Put the cutting in a clean jar of water and set it in a warm spot in bright, indirect light away from hot or cold drafts. Change the water every few days and wash the jar to eliminate any chance of algae or bacteria growing that could harm the plant.
Take the same kind of stem cutting as for water propagation. Leave it in the air for a couple of days and allow it to callus over to prevent the stem from rotting. Then, plant it in light, well-draining soil and set it in a warm, bright spot out of any drafts.