Was it a dry winter and spring? It may need extra water. If it has been too wet, then it’s reacting to poor drainage. If that’s the case, use a pitchfork to open up some holes in the ground around the base of the ninebark to help dry out the saturated dirt. You may have to dig it up and replant it. Curled leaves can also be a sign of herbicide spray damage. If the curled leaves are white, it’s powdery mildew. I hope this helps you find the answer to the problem.
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