well the paeony is the same as mine typical for end of year seasonal changes. So I reckon it will be the same for the other 2.

Do leaves turn yellow in Autumn? Many of them do.

Nope, the top two are chlorosis caused by micronutrient deficiency, probably lack of iron. In the UK, probably caused by chalky soil, overdose of lime, or extremely poor, sandy soil. An overdose of phosphate or light glyphosphate contamination can also cause this.

As Tug says, your soil is lacking nutrients - namely magnesium, nitrogen or iron. You'll need to do some research to find out which of these is lacking, and treat the soil accordingly.

Ok, thank you. I had a feeling it was not just autumnal yellowing. Will do some research.

well all I can say is my paeony does this and it has the right nutrients even though I do grow plants on/in alkaline soil. this and the camellia are the only 2 plants I pander to :o)

The paeony looks normal to me too. On the other hand, the lilac looks very sick...