Light. Needs full sun, at least 6 hours a day. It will not flower in low light.
Water. Water during the warm growing season, letting the soil dry between waterings. Soggy soil causes stem and root rot. Water much less in winter, when leaves often drop.
Soil and feeding. Use a well-drained cactus mix in pots, or a sandy raised bed. Skip organic mulch, which holds moisture. Feed in spring and summer with a slow-release fertilizer such as Bloom Special.
Size. Grows slowly to 3 ft or more; old plants can reach 4–6 ft. The trunk base swells with age.
Pruning. Rarely needed. To make it bushier, prune early in the growing season with clean pruners.
Problems to watch. Scale, mealybugs, mites and aphids; treat with Insecticidal Soap following the label. Hand-pick oleander caterpillars.
Good to know. All parts are poisonous if eaten, including to cats and dogs, and the sap irritates skin. Wear gloves. Cold below 40°F can damage branch tips.
Sources: UF/IFAS EDIS ENH1213/EP474: Florida Foliage House Plant Care: Adenium obesum · UF/IFAS Extension Charlotte County: Roses of the Desert · NC State Extension Plant Toolbox: Adenium obesum
