A nasty attack of ... what?

The balcony is now starting to turn green again, but not everything is looking happy. I think I may be losing my mandevilla and my hollyhocks.

The mandevilla has been slowly losing leaves all winter, and I hoped it was just a reaction to the cold. I left it outside this year, though well protected. But the leaf loss seems to be speeding up. Leaves start to turn brown, dry and then fall, so that the plant is getting a bare straggly look. A fungus infection? I've tried spraying, but it hasn't helped.

The leaves of the hollyhocks, on the other hand, first wilt and then slowly turn yellowish brown and die. There is also a whitish discolouration on some of the otherwise healthy looking leaves. Another fungus infection? I know hollyhocks are very prone to rust. Or a virus this time?

If anyone recognises the problems (and knows a remedy) please let me know. Otherwise I think I'm going to have to throw them all out.