To care for your Hoya "Black Margin," provide bright, indirect light to enhance the dark leaf margins, use a chunky, well-draining soil, and water only when the top 1–2 inches of soil are dry, allowing it to fully dry out between waterings to prevent root rot. Maintain average household to high humidity, a consistent temperature between 60-85°F (15-29°C), and feed monthly during spring and summer with a diluted, balanced liquid fertilizer.