Answer: Both of these plants need a well drained soil rather than one that is constantly wet or saturated. If you are using a watering system then you need to adjust it to avoid overwatering the area. Once established, both of these plants are quite drought tolerant and would not need watering except during very dry periods. At that time you would provide a slow deep soaking rather than frequent light waterings. You would also want to avoid wetting the foliage when you water as this can contribute to fungal infections. If your rock garden area is naturally wet, these might not be the best choice of plants for that area. Your local county extension and/or professional garden center staff should be able to help you analyze the growing conditions and identify plants that would do well there. They should also be able to help you with diagnosing the problem with your plants -- there are many possible causes for plant loss besides overwatering. Good luck with your rock garden!
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