Q.Poppies
Foliage growing in black color in places. I have downloaded a photograph, hope you can help. I have had fabulous displays for the last five years here in Sweden.

We did not receive the image.
https://www.gardeningknowhow.com/ornamental/flowers/poppy/growing-poppy-flowers.htm
Poppies can be susceptible to Downey Mildew, Grey Mold, Powdery Mildew, Tomato Wilt Virus, and Rhizoctonia Root Rot.
Without seeing the plants or leaves, and the time of year, I would suspect a fungus disease of some type.
Clean up and dispose of any dead leaves to prevent spread of disease.
Avoid water splashing onto the leaves with overhead watering and apply a fungicide to the remaining plants on a cool, overcast day.