To propagate an angel wing begonia, take a healthy stem cutting with several leaves. Remove the lower leaves and dip the end of the cutting in rooting hormone. Plant the cutting in a pot filled with a well-draining potting mix. Keep the potting mix moist and provide bright, indirect light. You can also propagate an angel wing begonia by leaf cuttings. Cut a leaf from the plant, making sure to include a small portion of the stem. Plant the leaf cutting in a pot filled with a well-draining potting mix. Keep the potting mix moist and provide bright, indirect light.