Glad you took the wild aster plunge Joanna. As far as wilds in the garden go, the New England Aster has never been a problem for me. Here they usually start bloom in late August hitting their stride in September. Five foot tall is about usual. They've never failed not to attract a considerable host of pollinators (a feat the commercial aster varieties can't duplicate). All years see a multitude of different BFs, different bees, and moths.
I've had mine so long, I don't remember if they bloomed the first year though were I to hazard a guess, I'd say probably.
They will self seed around but are easy to pull out once recognized. Where mine grow I've put some steel posts and half inch rebar stakes deep into the ground and usually tie parachute cord a/o thin rope around them to keep them upright.
To sum up, I think they'll yet bloom for you. The blooms on mine literally cover them. This year, I await as well.
(word of caution - don't take up with the white heath aster as it is too aggressive and ends up attracting multitudes of fly pollinators, though flies can be fun to take pics of too).
