Answer: Gardenias are one of our finest shrubs, growing to a height of about six feet in warmer areas of the United States. They have very attractive, shiny evergreen leaves that are about four inches long and, each spring, produce the loveliest of white flowers that are delightfully scented.
The natural range of gardenias is limited by their tropical heritage. Fortunately, they lend themselves to container culture and, by providing winter protection, may be enjoyed for years in the most severe climates.
In-ground planting should only be done In USDA hardiness zones 9 and 10 unless special winter protection is provided.
Mystery gardenia is a little hardier and keeps its larger, darker green foliage all year around. Because it is such a hardy plant, I suspect yours are suffering from a root problem (too much or too little water) and that's why the foliage has turned brown and droopy.
Gardenias require a rich, very acid soil (pH 4.5 to 5.0). An abundance of moisture and high humidity is the most important factor in successful gardenia culture. For flower buds to form and thrive, night temperatures need to be between 60-65F. During the day, temperatures should be 70-75F. A very constant, even temperature is required or buds will drop. Bright light is essential, but avoid direct mid-day sun in the summer. Hope this information helps you determine just what might be the cause of the root stress in your plants.
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