Fanal Astilbe Colony - Red Stems - June 2023

At what point can you consider a perennial 'established'?  

There are tons of posts out there on the Web that talk about this very topic - what it means to be well-established?  

It appears that there's no clear-cut answer as every plant in every garden has a different timeline.  

One of the colonies of perennials that I've been watching closely is also one of the colonies that was amongst the very first that we put in:  A dozen or so Fanal Astilbes.  They went in back in early Summer 2020 and came with a reputation for being finicky and wanting things like moist soil.   I posted in June 2020 and when I look back, I'm surprised by how far they've moved - I dug them up and transplanted them - over the years.  

But, how are they doing in June 2023 - their fourth growing season?  Seemingly....they are 'established'.  See below for a photo showing the red flower stems that have emerged from the green foliage in the south beds:

They're a really strong anchor to this side of the bed and despite moving on from them, I'm (now) drawn back to astilbe.  I recently planted three dark-foliage plants and know that I could use even more.  

The other thing that I'm watching this year is that I transplanted some young, pink Astilbes over to this bed last year.  I'm not sure if they'll bloom, but if they do, I'll have a decision to make:  run with a red and pink combo here?  Or, pick out the pink ones and find them a new home (border).  

This Fall also appears to be the right time to divide some of these - as some suggest that they do best when divided every three years.  Time to put these on my Fall 2023 to-do list.