Our David Austin roses threw out an arm of black spot (aimed at the eucalyptus) and it almost seems they fungally infected our euc as he had been fine for 3 years and was growing nicely into a tree.
Does anyone else have experience of such a cross-contamination?
Now the leaves of the euc are sagging and have pink spots and I have even noticed 2 patches of powdery white fungus on the bark.
Partner insists: "that's how they get their energy through the leaves- don't cut them off" (which I regret listening to regarding the roses' black spot) but eventually lopped the rose leaves off and disposed of.
I'm wondering whether it might be a good idea to chop the euc down to below the powdery infection so we are left with some bark but no branches. I have not previously pruned the euc in any way using gardening tools, so it is out of the question that those infected it.
Or should I spray it with something? It seems those leaves will have to come off though it really looks like it has the measles.
Regardless of how it happened, any thoughts on how to save the euc and future prevention?