Hi, I've got a passionfruit vine which has been in for 2 seasons, last season's crop was huge! It has been knocked hard by frosts over the last month or so, and I'm looking for advice about ongoing care.
Do I need to prune it? If so when and how?

Ooh, based on my experience, be really careful with pruning them. We had a glorious one by our back door. I had pruned off various bits and pieces as it seemed to need it. Then, by about five years old, it was just looking top heavy and in need of a good trim so I pruned it, not heavily, but just to get rid of the top-heavy mass of it. It didn't like it one bit. We ended up losing it and having to start again. Our one is very sheltered from frosts and not affected by them.

I think, if you're thinking of pruning, do a little bit now and then rather than a larger trim all at once.

I think as mine has been knocked by frosts, I'll leave it then. I know they are short lived, and intend to get another one started this year, so hopefully this one will come back as the weather warms up and see us for another year or three.

As much as I try I just can't seem to grow passionfruit. The leaves get munched by critters, fungal infections take hold and they just don't work.
I have tried all different places in my garden.
It is annoying as I do like passionfruit and would love to know how to grow them.

I'm afraid I can't offer much advice, mine grows against a wooden wall, where it gets sun through the afternoon, but not morning sun, it gets watered regularly in it's root zone but I haven't ever fed it, the soil is a sandy gravelly mix on top, but clay underneath. More luck than good management on my part I think.