Unhappy hydrangea - with pics

[Panticus]

I'm hoping some of the green thumbs on this thread will be able to help me out. I have a hydrangea in a pot that was going very well through summer but is looking very unhappy now we've hit the colder months (Southern Hemisphere).

It's in a pot and gets a lot of morning sun then goes into the shade. I noticed a week or so it had what looked like mould over some of the leaves so I trimmed them off. But it's also got a sort of rusting on the leaves which I've tried to capture in the pics.

I'm not much of a gardener so I'm at a bit of a loss. Too wet? Too dry? Potting mix lacking something?

Any ideas would be much appreciated

They are deciduous so if you are in the southern hemisphere it is going to be losing its leaves anyway. What sort of climate do you have - do you get winters with below freezing temperatures?

Thanks a@ahoyshipmates I didn't even think about whether or not they are deciduous. Daytime max temps are generally in the range of 10-16 Celsius throughout winter but we do get some frosty starts that could be minus 1 or 2 degrees. Could it be the frost do you think?