Looks very much like a Knautia macedonica. In which case it should have small Scabious like red/pink flowers.
And just to whet the appetite, this is the view from the backdoor.
Thought I would take some pictures before the forecast gales destroys the garden.
Should add that I have never seen as many shrubs go like this in 40 years of growing things. Odd thing is that shrubs next to the chlorotic ones are normal healthy green leafed, even when from the same family.
Cheers. Now to find somewhere that sells Epsom Salts.
Never seen as many shrubs with yellowing leaves before. In fact only ever seen it in Camellias grown in limy soil.
Rose Zepherine Drouhin
To show but a few.
Anyone suggest a course of action?
Try Paeony tenuifolia, that has different leaves to the other Paeony species.
We can only grow them at the bottom end of the poly-tunnel where it gets very warm. Have grown them for a few years, but they definitely would not crop outside here, too cold.
They are possibly what is known as pot worms. They are harmless, in the same way as earthworms of the ruddy hue are.
Try adding some lime to your soil.