the daylily rust (puccinia hemerocallidis) is not the same fungus as the aster rust. Your daylily rust is not believed to be able to survive your zone 5 ( but see information on the host plant) Google daylily rust and also aster rust for several execellent articles about spreading method and alternate hosts for spreading along with life cylce. While there may be more than what I was looking at just now, the main aster rust was coleosporium asterum.

My asters have rust. I've moved them twice, cut them to the ground, destroyed all old plant material, still rust. THey look terrible. So after the fourth year of rust I am giving up. Digging up all my asters and chucking them. And I am someone who moves "problem children" behind the barn or down to the pond. Not these guys. They're not even compost material.

Justmetoo- I found several rust names mentioned on the "Search results" I found while googling "Rust on Asters". Coleosporium asterum is definately what I have, I was just wondering if it overwintered here as that wasn't mentioned in the information I read. Looks like it does! :(

Gottagarden- Sorry about your asters! What variety do you have? The one I bought was 'Loke Viking' and it looks like it gets rust pretty bad. I have an unknown aster that starts out white and fades to a soft lilac color and has no rust. An unknown dark purple has a little rust but not so bad, this one also doesn't get much water so might be stressed as well. I noticed even my Malvas got rust!! ugh those are going out and staying out, didn't like their untidy look this year... and they reseeded everywhere! :O

I might give them a year in the garden and see how bad it looks...

I have several, Aster frikartii is the worst. Too bad, at my last house it was gorgeous, which is why I've been holding onto it for so long.