|The leaves on my gardinias turn black at the tips and continues at a slow pace toward the stem. It does not effect more than two or three leaves at a time.|
|Gardenias like average household temperatures (minimum 60F in the winter), bright light - but no direct sunlight - and moist soil. Use tepid, softened water. Mist the leaves frequently. If the leaves on your plants are turning black, it's a sign of low humidity near the plant, and too much water in the soil. In the winter it's best to water less frequently than when the plants are activiely growing.|
Try to adjust the growing environment and your plants should respond favorably to the new conditions.