Desert Rose (Adenium): Black Spots – Healed or Active?

Assessing the Black Areas

Small, dry black spots on a desert rose (Adenium obesum) that recently flowered after corrected care are likely healed scars from past fungal issues or sunburn. The yellowing base that resolved suggests the plant overcame the stress.

Recommendation: Leave Them Alone

• Do not cut into the caudex (swollen base)—risk of infection.
• You can gently scrape a spot with a knife edge to see if it's superficial.
• If dry, hard, and not spreading, they're cosmetic.

Ongoing Desert Rose Care

• Full sun year-round (south window).
• Water sparingly: Let soil dry deeply. Winter dormancy: cool (55–60°F), very little water, leaf drop normal.
• Well-draining soil: Cactus mix + extra perlite.
• Pot-bound preferred: Small pots, terra cotta.

Reference: https://www.tropicanursery.com/adenium/problems.htm#diseases