Where Have All My Asters Gone?!

I love perennial gardening because I don't have to plant flowers every year and then carefully water them... They come up by themselves and - most years - they are hardy enough to thrive without watering. Every three years or so, they need to be divided so that they won't encroach on neighboring plants... Sometimes I miss that critical step and the weaker plant disappears...

That must have happened a while back because I was recently reminded that I used to have a lot of lovely pink asters in my backyard beds in my early days of gardening...

What happened to them? They've disappeared!!

Maybe it's time to plant some again... Only this year, all I see (at my nearby Home Depot gardening center) is purple...