Mandevilla may occasionally face issues such as aphids, spider mites, mealybugs, yellowing leaves, or poor flowering. Inspect the plant regularly for pests and treat infestations with insecticidal soap or neem oil when necessary. Yellow leaves often indicate overwatering or poor drainage, while a lack of blooms may result from insufficient sunlight or excessive nitrogen fertilizer. Proper watering, adequate sunlight, and routine maintenance help keep the plant healthy and full of colorful flowers.