Answer: I think the combination of transplant shock and cutting down the foliage lead to the death of your ornamental grasses because by now they should have rooted and sent up new blades. It's normal for transplants to go through some stress but once the roots establish they usually perk right up. The problem was in cutting down the wilting grass blades. As long as they are green they are producing and transporting carbohydrates to the roots of the plant. By removing the plants' source of energy, you essentially shocked the plants even more. I'd try again - this fall - with healthy new specimens and just allow them to establish and send up new blades before pruning off the dead foliage. Fall is a better time to transplant. Early spring is another opportunity. That's when weather is cooler and rainfall more abundant, both of which help roots to establish. Best wishes with your ornamental grasses.
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