Adenium obesum, also known as desert rose, does not reliably produce seeds because of problems with pollination. New plants can be started from stem cuttings or by layering. For the home gardener, propagation by cuttings is usually simpler. The key to success with starting a new desert rose from a cutting is to start the plant immediately after cutting and to keep the cutting in a warm, humid environment.
Fill a cup with a moist mixture of 3 parts of perlite and 1 part peat moss.
Cut off a 5- to 6-inch section from the tip of a branch with clean, sharp pruning shears. Remove any leaves or flowers. Wear gloves when you cut Adenium obesum.
Dip the cut end into rooting hormone, according to package directions.
Poke a hole in the rooting medium using a pencil or small twig. Place the Adenium obesum cutting into the hole, burying the cut end halfway.
Place the desert rose cutting in a warm location or onto heating pad set on low. Cover loosely with a plastic bag to maintain humidity.
Check the moisture level twice a week and water just enough to keep the growing medium moist.
Allow eight to 10 weeks for the Adenium obesum cutting to root. Test the cutting by tugging lightly on the stem. A well-rooted cutting is anchored by the roots and resists the tug.
Pot the new desert rose in a small container of starter mix and allow it to grow for six to 12 months in a sheltered spot before transplanting it into the garden.