I lived in southeast PA (in Lenapehoking) for 18 years, ending in 2021 (i.e., until lasrt month). My experience was that there was no real consistent hub for permaculturish activity. There are numerous clusters that come and go, however. I will try to give a list of places...
First, I will start with Rodale, which someone already mentioned. The publisher was sold off to a big company in the last decade, so all that remains is the nonprofit in Kutztown and the now inaccessible "experimental farm" in the Allentown area. (Once called the working tree farm and a predecessor to Mollison's take-over of credit for perennial agriculture) In short, it was a huge hub in the prior century but is now not so and more focused on scaling up organic. It published Fukuoka's work in the U.S. back in the day though..
Phoenixville is a small hub of biodynamic agriculture as it has a Camphill community and a Waldorf school
Stonehedge Gardens in Tamaqua is a garden that has hosted a PA permaculture gathering a couple times in the last 5 years.
Lancaster has a permaculture project near the Conestoga river somewhere on what I think is city-owned land. Ecovillagers Cooperative used to be based there but is now in Philly and someone there might have a contact.
In Lancaster the backyard fruit growers is based. I was a member for decades and the grafting workshops and scion sharing every year is worth travelling for!!! They are a great community of fruit growers, but not a hub, per se. People are spread out.
The Frenchtown, NJ area is expensive, but there is a great organic cider orchard nearby, a Waldorf school on the PA side, at least one grower doing restorative riparian medicinal, etc. It is a hub of people who appreciate a forested Delaware River, but it is connected to NY money.
Berks County has quite a few small organic growers, but I dont know if there is much of a hub.
Bethlehem, where I was, is finally about to open its food co-op and it has a small permaculture garden near Lehigh University.
I won't comment on Philly, but there is urban aggie stuff happening there.
