Possible Disease infecting all plants.
Located in Australia, currently coming out of winter. I am having a problem that seems to be affecting all my plants in my garden. I am a new gardener so have no idea what it could be. Background: we have had a very wet winter and i had a bit of an aphid problem but none of the plants i have left are ones that had the aphids. I had some snow peas which I had to rip out over winter as they seemed to have blight so don't know if this is what is affecting everything. Starting from the bottom leaves usually, my plants have what looks like variegation or a little bit missing chlorophyll which gradually worsens, then the leaves start to turn yellow and eventually die. Some also have darker coloured patches on them. I have affected silverbeet, calendula, parsley, garlic and cornflowers, each one is displaying slightly different. Pictured is calendula early phases, calendula later, parlsey, cornflower and garlic.
Certified GKH Gardening Expert
They may all have aster yellows. In which case you would need to destroy the plants as there is no cure. For a definitive diagnoses you may want to consult a plant pathologist at a local university in Australia.