Adobe Camera Raw offers some adjustment of image noise under the Detail tab. I find it effective yet the adjustment can slightly degrade image sharpness. You may wish to give it a try.
UTMike wrote:
In editing photos from an exhibit at the New York Botanical Garden, I came across the attached photo. What you see in the download is a crop and edit that resulted in noise that I did not know how to address. Perhaps it cannot be addressed and I should consider this shot an "art" picture. I use LightRoom and Photo Shop, but I have little familiarity with PS.