Did you cut it back? It looks like the stems were cut, and it looks like flower buds are forming near the cuts. It's too early for Symphyotrichum novae-engliae to bloom ? I wonder if it's aster yellows?

Yes, it was cut back to keep it bushy. I see lace bugs, which would explain the leaf speckling, but I don’t think it explains the condition of the stalks and inner-growth.

Where are you located? Northern Virginia is under drought watch and several of my plants look like that.

Long Island, NY. We’ve been warering daily through the heat wave

I see many small grey shapes with what appear to be heads. They look like insects or mites of some kind but I can't make out details. The stippling definitely looks like pest damage to me. I don't think it's a cultivation issue.

Stick your finger into the soil and see if it's damp.

Like Floral, I think the stippling is beasties.

Look at all the browned leaves around the base of the plant.

The lower leaves are indeed dead or dying. But that doesn't rule out pests. Heavily attacked foliage will weaken and die. Am I the only person who can see these grey shapes? They're very obvious to my eye. And stippling is a common result of insect or mite damage.

I see them too, though I cannot make out what exactly they are.

The pests are lace bugs.

Right. So that's the stippling explained. I'm pretty sure such a heavy infestation would also cause the eventual browning and death of the leaves.