Thanks for your help with identifying this plant. I was able to search back through my photos using your suggestions and I suppose it is this aster. For some reason last fall I had decided it was something else, but didn’t take recent pictures. This is from 2006 so I should know it well by now, but must have put up a mental block.
The past several years I have not stayed on top of the garden and this plant is running thoughout my irises and taking over, as I showed in the last post. Guess I’ll start pulling it out again!
pbmGarden 
Glad the mystery has been solved! I fleetingly thought of aster, but since mine are only about an inch tall so far I immediately dismissed the idea! Nice to have such a pretty plant spreading, but I hope it won’t swamp out other plants.
Thanks Cathy. Unfortunately this plant is way too aggressive. It was just really planted in the wrong place. I was naive about its growth and spread habit.
Mine are a pale blue, but I don’t pull them all out at the bees really love it, so please leave a few for your bees!
I admit that was my thought too, but I was surprised it would be so invasive.
It’s pretty, if also exceptionally aggressive. I bought a Chilean aster that was said to spread “but not aggressively.” It’s turned out that my environment must be far more hospitable than that of the grower…
Happy weeding!
Weeding is sometimes very satisfying but only when the plants come up easily. This stuff is stubborn.
Time for a little chop back.
What?! I never would have guessed that! The flowers look just like our fleabane, but the new plants look nothing like ours.
Glad to read that somebody has been able to put a name to the culprit Suzie. It obviously likes where it is – maybe a bit too much.
Now to get rid of it. It’s growing by leaps and bounds.