I would plant them out soon so they are established in the garden prior to the winter. That is what I usually do, mid/late September.

Thank you

Any tips on the dreaded rust?

avoid growing them in the same place as in previous years. Try and keep a good air flow around the plants too.
if they get rust do not compost them in your own bins and put them in the council bins or if you can burn them.

Thanks again.

When I grew Hhocks I used to spray them against rust twice a year. First when they were still young & again before they flowered. I sprayed the ground around them also, as they came up every year. Sometimes I’d pick the odd affected leaf off & dispose of it as Sb says.

So far, no rust here, but we lost most of them to molluscs before there was time for rust to appear.