Hoya propagation
Making new plants from cuttings and layers, and what the sources say about rooting in water versus potting mix.
How to take hoya stem cuttings, step by step
Take a healthy piece of last year's stem in spring or early summer, with at least two nodes. Remove the lower leaves, insert the cutting in a moist, sterile, well-drained rooting medium (or stand it in water), cover it to keep humidity high, and keep it in bright, indirect light. Pot it up once the roots are about 2.5 cm (1 inch) long.