We have a mature tree, Varigated Poplar - I believe, The leaves are turning black and dropping off. Is it possibly Ash Dieback?? Any suggestions please.
Just a thought, but I wondered if the lack of chlorophyll in the leaf may cause poor photosynthesis to take place and resulting in the leaves turning black and dropping off.
This may also explain why its often recommended that variegated plants are planed in the shade, to avoid leaf-scorch.