Answer: This plant, Inkberry or Ilex glabra, prefers a moist and acid soil to do its best. It grows in swampy areas in the wild, so this is an indication of its preferred soil type. The symptoms you describe could be caused by the plant reaching its limit for moisture stress. Transplanting in the heat of mid summer is particularly stressful for plants. A newly transplanted shrub would need careful attention to watering all season up until the ground freezes, with the moisture being able to penetrate not only the root ball area of potting soil but also out into the native soil so that the roots would have a surrounding moist area to grow into. This would be applied by a deep soaking and the soil moisture would be protected by several inches of mulch. The less frequent but deep soaking would be far more effective than a daily light sprinkling in terms of maintaining an even soil moisture, especially in periods of drought as we have had this summer.
Sometimes a shrub simply will not root out beyond the original soil mass and this can cause it to die of water stress, it can also essentially strangle itself by virtue of encircling roots. You might want to dig one up and see if the roots have grown at all and in what pattern.
You might also wish to consult with the nursery where you purchased the plants to see if they have any ideas. I'm sorry about your shrubs.
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