The short answer
Take a healthy stem cutting with at least one node, then place the node in water while keeping leaves above the waterline. Roots develop from the node, not from a leaf blade alone.
Why this happens
A node is the point where a leaf and aerial root join the stem. Bright indirect light and clean water support rooting; strong direct sun can overheat the container.
What to do
- Cut below a node with clean scissors.
- Remove any leaf that would sit underwater.
- Refresh water regularly and rinse the container.
- Move to moist potting mix once several roots are a few inches long.
Keep in mind
Newly potted water-rooted cuttings need a gradual transition. Keep the mix lightly moist at first, never waterlogged.