1: 1. Overwatering: Yellow leaves could indicate too much water. Allow soil to dry before watering again. 2. Poor drainage: Ensure proper drainage to avoid root rot. 3. Lack of sunlight: Gardenias thrive in full sun or partial shade.

2: 4. Improper pH: Gardenias prefer slightly acidic soil with a pH of 5.0-6.0. 5. Nutrient deficiencies: Feed with a fertilizer formulated for acid-loving plants. 6. Pruning mistakes: Trim after flowering to promote new growth.

3: 7. Pest infestations: Monitor for aphids, mealybugs, and scale insects. Use insecticidal soap if necessary. 8. Disease susceptibility: Powdery mildew and root rot are common issues. Treat with fungicides. 9. Temperature extremes: Protect from frost in winter and provide adequate ventilation in summer.

4: 10. Overcrowding: Plant gardenias with enough space for proper air circulation. 11. Inadequate mulching: Apply mulch to retain moisture and regulate soil temperature. 12. Untimely repotting: Transplant in spring when roots outgrow the container.

5: 13. Inconsistent watering: Maintain a consistent watering schedule to prevent stress. 14. Improper planting depth: Plant at the same depth as in the nursery pot. 15. Lack of regular maintenance: Prune, fertilize, and monitor for pests regularly.

6: 16. Neglecting soil quality: Use well-draining, fertile soil rich in organic matter. 17. Overfertilizing: Follow recommended dosage to avoid nutrient burn. 18. Selecting the wrong variety: Choose a gardenia cultivar suitable for your climate zone.

7: 19. Ignoring weather conditions: Provide frost protection during winter months. 20. Not addressing yellowing leaves: Yellow leaves may indicate nutrient deficiencies or water stress. 21. Failure to monitor humidity levels: Gardenias prefer high humidity levels.

8: 22. Inadequate air circulation: Prune to promote airflow and prevent fungal diseases. 23. Avoiding regular inspections: Check for signs of pests and diseases weekly. 24. Not providing adequate support: Stake or trellis young gardenias to prevent bending.

9: 25. Overlooking signs of distress: Act promptly to address issues before they escalate. 26. Lack of research: Educate yourself on gardenia care to ensure success. 27. Enjoy the process: With proper care, your gardenias will reward you with fragrant blooms.