Q.Black leaf on Duranta bushes
I have a line of 9 young Duranta bushes in clay soil in Lawrence NSW. I dug out about 300 mm dia and the same depth, inserted som Gypsum and filled with good garden soil. Around half of these plants have significant proportion of the leaves that have turned black. Quite dark black not brown and it’s not Stott, the colour does not rub. Off on ones fingers if touched. Is this normal or is it a disease Thanks in advance
Regards John McBratney Lawrence, NSW

Duranta need loamy and well draining soil. It sounds like your clay soil is not suitable for your plants.
The black leaves are likely due to die off.
Further amendment would be needed to support healthy Duranta growth.
https://www.gardeningknowhow.com/ornamental/flowers/duranta/care-of-duranta-plants.htm