Question about dividing perennials

Question about dividing perennials

Hi! I'm looking for input regarding how best to divide my Goldstrum rudbeckia and when it should be done. I'm in Zone 5, SE Michigan. The plants are beginning to over-crowd the their bed. I am wondering, should I just cut back the foliage and divide them or wait till it dies back on its own? The weather is just starting to cool down here. I also want to be able to transfer the divisions to another area around the house. Thanks muchly in advance!!!
ello.

ello.

New ^_^

New ^_^

Help! stunned baby blackbird

Help! stunned baby blackbird

We Have TOMATOES!!!

We Have TOMATOES!!!

Audrey III? Help on plant identification:

Audrey III? Help on plant identification:

I gave you an inch, you want a house with a yard.

I gave you an inch, you want a house with a yard.