Answer: Based on your description I am not able to give you a firm diagnosis; these are usually trouble free plants. However they are potentially subject to some problems such as being rootbound due to poor planting technique, or diseases such as verticillium wilt, or then there is always the possibility of something unusual happening such as accidental herbicide exposure can also happen. I would suggest you work with your county extension and/or professional nurseryman to try to determine what has happened. I'm sorry I can't be more specific for you long distance.
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